Merge branch 'tb/apply-with-crlf' into next
[gitweb.git] / diff.c
diff --git a/diff.c b/diff.c
index 8c78fce49dc5fa9e1215eb3bdb88e1f5e7f9d2c6..ac4023d30b81cc316393b46572d6808b68728127 100644 (file)
--- a/diff.c
+++ b/diff.c
@@ -2,6 +2,7 @@
  * Copyright (C) 2005 Junio C Hamano
  */
 #include "cache.h"
+#include "config.h"
 #include "tempfile.h"
 #include "quote.h"
 #include "diff.h"
 #include "userdiff.h"
 #include "submodule-config.h"
 #include "submodule.h"
+#include "hashmap.h"
 #include "ll-merge.h"
 #include "string-list.h"
 #include "argv-array.h"
+#include "graph.h"
 
 #ifdef NO_FAST_WORKING_DIRECTORY
 #define FAST_WORKING_DIRECTORY 0
 #endif
 
 static int diff_detect_rename_default;
-static int diff_compaction_heuristic; /* experimental */
+static int diff_indent_heuristic = 1;
 static int diff_rename_limit_default = 400;
 static int diff_suppress_blank_empty;
 static int diff_use_color_default = -1;
+static int diff_color_moved_default;
 static int diff_context_default = 3;
+static int diff_interhunk_context_default;
 static const char *diff_word_regex_cfg;
 static const char *external_diff_cmd_cfg;
 static const char *diff_order_file_cfg;
@@ -41,6 +46,7 @@ static int diff_stat_graph_width;
 static int diff_dirstat_permille_default = 30;
 static struct diff_options default_diff_options;
 static long diff_algorithm;
+static unsigned ws_error_highlight_default = WSEH_NEW;
 
 static char diff_colors[][COLOR_MAXLEN] = {
        GIT_COLOR_RESET,
@@ -52,8 +58,21 @@ static char diff_colors[][COLOR_MAXLEN] = {
        GIT_COLOR_YELLOW,       /* COMMIT */
        GIT_COLOR_BG_RED,       /* WHITESPACE */
        GIT_COLOR_NORMAL,       /* FUNCINFO */
+       GIT_COLOR_BOLD_MAGENTA, /* OLD_MOVED */
+       GIT_COLOR_BOLD_BLUE,    /* OLD_MOVED ALTERNATIVE */
+       GIT_COLOR_FAINT,        /* OLD_MOVED_DIM */
+       GIT_COLOR_FAINT_ITALIC, /* OLD_MOVED_ALTERNATIVE_DIM */
+       GIT_COLOR_BOLD_CYAN,    /* NEW_MOVED */
+       GIT_COLOR_BOLD_YELLOW,  /* NEW_MOVED ALTERNATIVE */
+       GIT_COLOR_FAINT,        /* NEW_MOVED_DIM */
+       GIT_COLOR_FAINT_ITALIC, /* NEW_MOVED_ALTERNATIVE_DIM */
 };
 
+static NORETURN void die_want_option(const char *option_name)
+{
+       die(_("option '%s' requires a value"), option_name);
+}
+
 static int parse_diff_color_slot(const char *var)
 {
        if (!strcasecmp(var, "context") || !strcasecmp(var, "plain"))
@@ -72,6 +91,22 @@ static int parse_diff_color_slot(const char *var)
                return DIFF_WHITESPACE;
        if (!strcasecmp(var, "func"))
                return DIFF_FUNCINFO;
+       if (!strcasecmp(var, "oldmoved"))
+               return DIFF_FILE_OLD_MOVED;
+       if (!strcasecmp(var, "oldmovedalternative"))
+               return DIFF_FILE_OLD_MOVED_ALT;
+       if (!strcasecmp(var, "oldmoveddimmed"))
+               return DIFF_FILE_OLD_MOVED_DIM;
+       if (!strcasecmp(var, "oldmovedalternativedimmed"))
+               return DIFF_FILE_OLD_MOVED_ALT_DIM;
+       if (!strcasecmp(var, "newmoved"))
+               return DIFF_FILE_NEW_MOVED;
+       if (!strcasecmp(var, "newmovedalternative"))
+               return DIFF_FILE_NEW_MOVED_ALT;
+       if (!strcasecmp(var, "newmoveddimmed"))
+               return DIFF_FILE_NEW_MOVED_DIM;
+       if (!strcasecmp(var, "newmovedalternativedimmed"))
+               return DIFF_FILE_NEW_MOVED_ALT_DIM;
        return -1;
 }
 
@@ -131,9 +166,11 @@ static int parse_dirstat_params(struct diff_options *options, const char *params
 static int parse_submodule_params(struct diff_options *options, const char *value)
 {
        if (!strcmp(value, "log"))
-               DIFF_OPT_SET(options, SUBMODULE_LOG);
+               options->submodule_format = DIFF_SUBMODULE_LOG;
        else if (!strcmp(value, "short"))
-               DIFF_OPT_CLR(options, SUBMODULE_LOG);
+               options->submodule_format = DIFF_SUBMODULE_SHORT;
+       else if (!strcmp(value, "diff"))
+               options->submodule_format = DIFF_SUBMODULE_INLINE_DIFF;
        else
                return -1;
        return 0;
@@ -163,6 +200,43 @@ long parse_algorithm_value(const char *value)
        return -1;
 }
 
+static int parse_one_token(const char **arg, const char *token)
+{
+       const char *rest;
+       if (skip_prefix(*arg, token, &rest) && (!*rest || *rest == ',')) {
+               *arg = rest;
+               return 1;
+       }
+       return 0;
+}
+
+static int parse_ws_error_highlight(const char *arg)
+{
+       const char *orig_arg = arg;
+       unsigned val = 0;
+
+       while (*arg) {
+               if (parse_one_token(&arg, "none"))
+                       val = 0;
+               else if (parse_one_token(&arg, "default"))
+                       val = WSEH_NEW;
+               else if (parse_one_token(&arg, "all"))
+                       val = WSEH_NEW | WSEH_OLD | WSEH_CONTEXT;
+               else if (parse_one_token(&arg, "new"))
+                       val |= WSEH_NEW;
+               else if (parse_one_token(&arg, "old"))
+                       val |= WSEH_OLD;
+               else if (parse_one_token(&arg, "context"))
+                       val |= WSEH_CONTEXT;
+               else {
+                       return -1 - (int)(arg - orig_arg);
+               }
+               if (*arg)
+                       arg++;
+       }
+       return val;
+}
+
 /*
  * These are to give UI layer defaults.
  * The core-level commands such as git-diff-files should
@@ -174,24 +248,65 @@ void init_diff_ui_defaults(void)
        diff_detect_rename_default = 1;
 }
 
+int git_diff_heuristic_config(const char *var, const char *value, void *cb)
+{
+       if (!strcmp(var, "diff.indentheuristic"))
+               diff_indent_heuristic = git_config_bool(var, value);
+       return 0;
+}
+
+static int parse_color_moved(const char *arg)
+{
+       switch (git_parse_maybe_bool(arg)) {
+       case 0:
+               return COLOR_MOVED_NO;
+       case 1:
+               return COLOR_MOVED_DEFAULT;
+       default:
+               break;
+       }
+
+       if (!strcmp(arg, "no"))
+               return COLOR_MOVED_NO;
+       else if (!strcmp(arg, "plain"))
+               return COLOR_MOVED_PLAIN;
+       else if (!strcmp(arg, "zebra"))
+               return COLOR_MOVED_ZEBRA;
+       else if (!strcmp(arg, "default"))
+               return COLOR_MOVED_DEFAULT;
+       else if (!strcmp(arg, "dimmed_zebra"))
+               return COLOR_MOVED_ZEBRA_DIM;
+       else
+               return error(_("color moved setting must be one of 'no', 'default', 'zebra', 'dimmed_zebra', 'plain'"));
+}
+
 int git_diff_ui_config(const char *var, const char *value, void *cb)
 {
        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
                diff_use_color_default = git_config_colorbool(var, value);
                return 0;
        }
+       if (!strcmp(var, "diff.colormoved")) {
+               int cm = parse_color_moved(value);
+               if (cm < 0)
+                       return -1;
+               diff_color_moved_default = cm;
+               return 0;
+       }
        if (!strcmp(var, "diff.context")) {
                diff_context_default = git_config_int(var, value);
                if (diff_context_default < 0)
                        return -1;
                return 0;
        }
-       if (!strcmp(var, "diff.renames")) {
-               diff_detect_rename_default = git_config_rename(var, value);
+       if (!strcmp(var, "diff.interhunkcontext")) {
+               diff_interhunk_context_default = git_config_int(var, value);
+               if (diff_interhunk_context_default < 0)
+                       return -1;
                return 0;
        }
-       if (!strcmp(var, "diff.compactionheuristic")) {
-               diff_compaction_heuristic = git_config_bool(var, value);
+       if (!strcmp(var, "diff.renames")) {
+               diff_detect_rename_default = git_config_rename(var, value);
                return 0;
        }
        if (!strcmp(var, "diff.autorefreshindex")) {
@@ -234,8 +349,13 @@ int git_diff_ui_config(const char *var, const char *value, void *cb)
                return 0;
        }
 
-       if (git_color_config(var, value, cb) < 0)
-               return -1;
+       if (!strcmp(var, "diff.wserrorhighlight")) {
+               int val = parse_ws_error_highlight(value);
+               if (val < 0)
+                       return -1;
+               ws_error_highlight_default = val;
+               return 0;
+       }
 
        return git_diff_basic_config(var, value, cb);
 }
@@ -284,6 +404,9 @@ int git_diff_basic_config(const char *var, const char *value, void *cb)
        if (starts_with(var, "submodule."))
                return parse_submodule_config_option(var, value);
 
+       if (git_diff_heuristic_config(var, value, cb) < 0)
+               return -1;
+
        return git_default_config(var, value, cb);
 }
 
@@ -331,7 +454,7 @@ static struct diff_tempfile {
         */
        const char *name;
 
-       char hex[GIT_SHA1_HEXSZ + 1];
+       char hex[GIT_MAX_HEXSZ + 1];
        char mode[10];
 
        /*
@@ -341,8 +464,6 @@ static struct diff_tempfile {
        struct tempfile tempfile;
 } diff_temp[2];
 
-typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
-
 struct emit_callback {
        int color_diff;
        unsigned ws_rule;
@@ -350,7 +471,6 @@ struct emit_callback {
        int blank_at_eof_in_postimage;
        int lno_in_preimage;
        int lno_in_postimage;
-       sane_truncate_fn truncate;
        const char **label_path;
        struct diff_words_data *diff_words;
        struct diff_options *opt;
@@ -492,68 +612,735 @@ static void emit_line(struct diff_options *o, const char *set, const char *reset
        emit_line_0(o, set, reset, line[0], line+1, len-1);
 }
 
-static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
+enum diff_symbol {
+       DIFF_SYMBOL_BINARY_DIFF_HEADER,
+       DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
+       DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
+       DIFF_SYMBOL_BINARY_DIFF_BODY,
+       DIFF_SYMBOL_BINARY_DIFF_FOOTER,
+       DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
+       DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
+       DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
+       DIFF_SYMBOL_STATS_LINE,
+       DIFF_SYMBOL_WORD_DIFF,
+       DIFF_SYMBOL_STAT_SEP,
+       DIFF_SYMBOL_SUMMARY,
+       DIFF_SYMBOL_SUBMODULE_ADD,
+       DIFF_SYMBOL_SUBMODULE_DEL,
+       DIFF_SYMBOL_SUBMODULE_UNTRACKED,
+       DIFF_SYMBOL_SUBMODULE_MODIFIED,
+       DIFF_SYMBOL_SUBMODULE_HEADER,
+       DIFF_SYMBOL_SUBMODULE_ERROR,
+       DIFF_SYMBOL_SUBMODULE_PIPETHROUGH,
+       DIFF_SYMBOL_REWRITE_DIFF,
+       DIFF_SYMBOL_BINARY_FILES,
+       DIFF_SYMBOL_HEADER,
+       DIFF_SYMBOL_FILEPAIR_PLUS,
+       DIFF_SYMBOL_FILEPAIR_MINUS,
+       DIFF_SYMBOL_WORDS_PORCELAIN,
+       DIFF_SYMBOL_WORDS,
+       DIFF_SYMBOL_CONTEXT,
+       DIFF_SYMBOL_CONTEXT_INCOMPLETE,
+       DIFF_SYMBOL_PLUS,
+       DIFF_SYMBOL_MINUS,
+       DIFF_SYMBOL_NO_LF_EOF,
+       DIFF_SYMBOL_CONTEXT_FRAGINFO,
+       DIFF_SYMBOL_CONTEXT_MARKER,
+       DIFF_SYMBOL_SEPARATOR
+};
+/*
+ * Flags for content lines:
+ * 0..12 are whitespace rules
+ * 13-15 are WSEH_NEW | WSEH_OLD | WSEH_CONTEXT
+ * 16 is marking if the line is blank at EOF
+ */
+#define DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF     (1<<16)
+#define DIFF_SYMBOL_MOVED_LINE                 (1<<17)
+#define DIFF_SYMBOL_MOVED_LINE_ALT             (1<<18)
+#define DIFF_SYMBOL_MOVED_LINE_UNINTERESTING   (1<<19)
+#define DIFF_SYMBOL_CONTENT_WS_MASK (WSEH_NEW | WSEH_OLD | WSEH_CONTEXT | WS_RULE_MASK)
+
+/*
+ * This struct is used when we need to buffer the output of the diff output.
+ *
+ * NEEDSWORK: Instead of storing a copy of the line, add an offset pointer
+ * into the pre/post image file. This pointer could be a union with the
+ * line pointer. By storing an offset into the file instead of the literal line,
+ * we can decrease the memory footprint for the buffered output. At first we
+ * may want to only have indirection for the content lines, but we could also
+ * enhance the state for emitting prefabricated lines, e.g. the similarity
+ * score line or hunk/file headers would only need to store a number or path
+ * and then the output can be constructed later on depending on state.
+ */
+struct emitted_diff_symbol {
+       const char *line;
+       int len;
+       int flags;
+       enum diff_symbol s;
+};
+#define EMITTED_DIFF_SYMBOL_INIT {NULL}
+
+struct emitted_diff_symbols {
+       struct emitted_diff_symbol *buf;
+       int nr, alloc;
+};
+#define EMITTED_DIFF_SYMBOLS_INIT {NULL, 0, 0}
+
+static void append_emitted_diff_symbol(struct diff_options *o,
+                                      struct emitted_diff_symbol *e)
 {
-       if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
-             ecbdata->blank_at_eof_in_preimage &&
-             ecbdata->blank_at_eof_in_postimage &&
-             ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
-             ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
-               return 0;
-       return ws_blank_line(line, len, ecbdata->ws_rule);
+       struct emitted_diff_symbol *f;
+
+       ALLOC_GROW(o->emitted_symbols->buf,
+                  o->emitted_symbols->nr + 1,
+                  o->emitted_symbols->alloc);
+       f = &o->emitted_symbols->buf[o->emitted_symbols->nr++];
+
+       memcpy(f, e, sizeof(struct emitted_diff_symbol));
+       f->line = e->line ? xmemdupz(e->line, e->len) : NULL;
 }
 
-static void emit_line_checked(const char *reset,
-                             struct emit_callback *ecbdata,
-                             const char *line, int len,
-                             enum color_diff color,
-                             unsigned ws_error_highlight,
-                             char sign)
+struct moved_entry {
+       struct hashmap_entry ent;
+       const struct emitted_diff_symbol *es;
+       struct moved_entry *next_line;
+};
+
+static int next_byte(const char **cp, const char **endp,
+                    const struct diff_options *diffopt)
+{
+       int retval;
+
+       if (*cp > *endp)
+               return -1;
+
+       if (DIFF_XDL_TST(diffopt, IGNORE_WHITESPACE_CHANGE)) {
+               while (*cp < *endp && isspace(**cp))
+                       (*cp)++;
+               /*
+                * After skipping a couple of whitespaces, we still have to
+                * account for one space.
+                */
+               return (int)' ';
+       }
+
+       if (DIFF_XDL_TST(diffopt, IGNORE_WHITESPACE)) {
+               while (*cp < *endp && isspace(**cp))
+                       (*cp)++;
+               /* return the first non-ws character via the usual below */
+       }
+
+       retval = (unsigned char)(**cp);
+       (*cp)++;
+       return retval;
+}
+
+static int moved_entry_cmp(const struct diff_options *diffopt,
+                          const struct moved_entry *a,
+                          const struct moved_entry *b,
+                          const void *keydata)
+{
+       const char *ap = a->es->line, *ae = a->es->line + a->es->len;
+       const char *bp = b->es->line, *be = b->es->line + b->es->len;
+
+       if (!(diffopt->xdl_opts & XDF_WHITESPACE_FLAGS))
+               return a->es->len != b->es->len  || memcmp(ap, bp, a->es->len);
+
+       if (DIFF_XDL_TST(diffopt, IGNORE_WHITESPACE_AT_EOL)) {
+               while (ae > ap && isspace(*ae))
+                       ae--;
+               while (be > bp && isspace(*be))
+                       be--;
+       }
+
+       while (1) {
+               int ca, cb;
+               ca = next_byte(&ap, &ae, diffopt);
+               cb = next_byte(&bp, &be, diffopt);
+               if (ca != cb)
+                       return 1;
+               if (ca < 0)
+                       return 0;
+       }
+}
+
+static unsigned get_string_hash(struct emitted_diff_symbol *es, struct diff_options *o)
+{
+       if (o->xdl_opts & XDF_WHITESPACE_FLAGS) {
+               static struct strbuf sb = STRBUF_INIT;
+               const char *ap = es->line, *ae = es->line + es->len;
+               int c;
+
+               strbuf_reset(&sb);
+               while (ae > ap && isspace(*ae))
+                       ae--;
+               while ((c = next_byte(&ap, &ae, o)) > 0)
+                       strbuf_addch(&sb, c);
+
+               return memhash(sb.buf, sb.len);
+       } else {
+               return memhash(es->line, es->len);
+       }
+}
+
+static struct moved_entry *prepare_entry(struct diff_options *o,
+                                        int line_no)
+{
+       struct moved_entry *ret = xmalloc(sizeof(*ret));
+       struct emitted_diff_symbol *l = &o->emitted_symbols->buf[line_no];
+
+       ret->ent.hash = get_string_hash(l, o);
+       ret->es = l;
+       ret->next_line = NULL;
+
+       return ret;
+}
+
+static void add_lines_to_move_detection(struct diff_options *o,
+                                       struct hashmap *add_lines,
+                                       struct hashmap *del_lines)
+{
+       struct moved_entry *prev_line = NULL;
+
+       int n;
+       for (n = 0; n < o->emitted_symbols->nr; n++) {
+               struct hashmap *hm;
+               struct moved_entry *key;
+
+               switch (o->emitted_symbols->buf[n].s) {
+               case DIFF_SYMBOL_PLUS:
+                       hm = add_lines;
+                       break;
+               case DIFF_SYMBOL_MINUS:
+                       hm = del_lines;
+                       break;
+               default:
+                       prev_line = NULL;
+                       continue;
+               }
+
+               key = prepare_entry(o, n);
+               if (prev_line && prev_line->es->s == o->emitted_symbols->buf[n].s)
+                       prev_line->next_line = key;
+
+               hashmap_add(hm, key);
+               prev_line = key;
+       }
+}
+
+static int shrink_potential_moved_blocks(struct moved_entry **pmb,
+                                        int pmb_nr)
+{
+       int lp, rp;
+
+       /* Shrink the set of potential block to the remaining running */
+       for (lp = 0, rp = pmb_nr - 1; lp <= rp;) {
+               while (lp < pmb_nr && pmb[lp])
+                       lp++;
+               /* lp points at the first NULL now */
+
+               while (rp > -1 && !pmb[rp])
+                       rp--;
+               /* rp points at the last non-NULL */
+
+               if (lp < pmb_nr && rp > -1 && lp < rp) {
+                       pmb[lp] = pmb[rp];
+                       pmb[rp] = NULL;
+                       rp--;
+                       lp++;
+               }
+       }
+
+       /* Remember the number of running sets */
+       return rp + 1;
+}
+
+/*
+ * If o->color_moved is COLOR_MOVED_PLAIN, this function does nothing.
+ *
+ * Otherwise, if the last block has fewer alphanumeric characters than
+ * COLOR_MOVED_MIN_ALNUM_COUNT, unset DIFF_SYMBOL_MOVED_LINE on all lines in
+ * that block.
+ *
+ * The last block consists of the (n - block_length)'th line up to but not
+ * including the nth line.
+ *
+ * NEEDSWORK: This uses the same heuristic as blame_entry_score() in blame.c.
+ * Think of a way to unify them.
+ */
+static void adjust_last_block(struct diff_options *o, int n, int block_length)
+{
+       int i, alnum_count = 0;
+       if (o->color_moved == COLOR_MOVED_PLAIN)
+               return;
+       for (i = 1; i < block_length + 1; i++) {
+               const char *c = o->emitted_symbols->buf[n - i].line;
+               for (; *c; c++) {
+                       if (!isalnum(*c))
+                               continue;
+                       alnum_count++;
+                       if (alnum_count >= COLOR_MOVED_MIN_ALNUM_COUNT)
+                               return;
+               }
+       }
+       for (i = 1; i < block_length + 1; i++)
+               o->emitted_symbols->buf[n - i].flags &= ~DIFF_SYMBOL_MOVED_LINE;
+}
+
+/* Find blocks of moved code, delegate actual coloring decision to helper */
+static void mark_color_as_moved(struct diff_options *o,
+                               struct hashmap *add_lines,
+                               struct hashmap *del_lines)
+{
+       struct moved_entry **pmb = NULL; /* potentially moved blocks */
+       int pmb_nr = 0, pmb_alloc = 0;
+       int n, flipped_block = 1, block_length = 0;
+
+
+       for (n = 0; n < o->emitted_symbols->nr; n++) {
+               struct hashmap *hm = NULL;
+               struct moved_entry *key;
+               struct moved_entry *match = NULL;
+               struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
+               int i;
+
+               switch (l->s) {
+               case DIFF_SYMBOL_PLUS:
+                       hm = del_lines;
+                       key = prepare_entry(o, n);
+                       match = hashmap_get(hm, key, o);
+                       free(key);
+                       break;
+               case DIFF_SYMBOL_MINUS:
+                       hm = add_lines;
+                       key = prepare_entry(o, n);
+                       match = hashmap_get(hm, key, o);
+                       free(key);
+                       break;
+               default:
+                       flipped_block = 1;
+               }
+
+               if (!match) {
+                       adjust_last_block(o, n, block_length);
+                       pmb_nr = 0;
+                       block_length = 0;
+                       continue;
+               }
+
+               l->flags |= DIFF_SYMBOL_MOVED_LINE;
+
+               if (o->color_moved == COLOR_MOVED_PLAIN)
+                       continue;
+
+               /* Check any potential block runs, advance each or nullify */
+               for (i = 0; i < pmb_nr; i++) {
+                       struct moved_entry *p = pmb[i];
+                       struct moved_entry *pnext = (p && p->next_line) ?
+                                       p->next_line : NULL;
+                       if (pnext && !hm->cmpfn(o, pnext, match, NULL)) {
+                               pmb[i] = p->next_line;
+                       } else {
+                               pmb[i] = NULL;
+                       }
+               }
+
+               pmb_nr = shrink_potential_moved_blocks(pmb, pmb_nr);
+
+               if (pmb_nr == 0) {
+                       /*
+                        * The current line is the start of a new block.
+                        * Setup the set of potential blocks.
+                        */
+                       for (; match; match = hashmap_get_next(hm, match)) {
+                               ALLOC_GROW(pmb, pmb_nr + 1, pmb_alloc);
+                               pmb[pmb_nr++] = match;
+                       }
+
+                       flipped_block = (flipped_block + 1) % 2;
+
+                       adjust_last_block(o, n, block_length);
+                       block_length = 0;
+               }
+
+               block_length++;
+
+               if (flipped_block)
+                       l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
+       }
+       adjust_last_block(o, n, block_length);
+
+       free(pmb);
+}
+
+#define DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK \
+  (DIFF_SYMBOL_MOVED_LINE | DIFF_SYMBOL_MOVED_LINE_ALT)
+static void dim_moved_lines(struct diff_options *o)
+{
+       int n;
+       for (n = 0; n < o->emitted_symbols->nr; n++) {
+               struct emitted_diff_symbol *prev = (n != 0) ?
+                               &o->emitted_symbols->buf[n - 1] : NULL;
+               struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
+               struct emitted_diff_symbol *next =
+                               (n < o->emitted_symbols->nr - 1) ?
+                               &o->emitted_symbols->buf[n + 1] : NULL;
+
+               /* Not a plus or minus line? */
+               if (l->s != DIFF_SYMBOL_PLUS && l->s != DIFF_SYMBOL_MINUS)
+                       continue;
+
+               /* Not a moved line? */
+               if (!(l->flags & DIFF_SYMBOL_MOVED_LINE))
+                       continue;
+
+               /*
+                * If prev or next are not a plus or minus line,
+                * pretend they don't exist
+                */
+               if (prev && prev->s != DIFF_SYMBOL_PLUS &&
+                           prev->s != DIFF_SYMBOL_MINUS)
+                       prev = NULL;
+               if (next && next->s != DIFF_SYMBOL_PLUS &&
+                           next->s != DIFF_SYMBOL_MINUS)
+                       next = NULL;
+
+               /* Inside a block? */
+               if ((prev &&
+                   (prev->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
+                   (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK)) &&
+                   (next &&
+                   (next->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK) ==
+                   (l->flags & DIFF_SYMBOL_MOVED_LINE_ZEBRA_MASK))) {
+                       l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
+                       continue;
+               }
+
+               /* Check if we are at an interesting bound: */
+               if (prev && (prev->flags & DIFF_SYMBOL_MOVED_LINE) &&
+                   (prev->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
+                      (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
+                       continue;
+               if (next && (next->flags & DIFF_SYMBOL_MOVED_LINE) &&
+                   (next->flags & DIFF_SYMBOL_MOVED_LINE_ALT) !=
+                      (l->flags & DIFF_SYMBOL_MOVED_LINE_ALT))
+                       continue;
+
+               /*
+                * The boundary to prev and next are not interesting,
+                * so this line is not interesting as a whole
+                */
+               l->flags |= DIFF_SYMBOL_MOVED_LINE_UNINTERESTING;
+       }
+}
+
+static void emit_line_ws_markup(struct diff_options *o,
+                               const char *set, const char *reset,
+                               const char *line, int len, char sign,
+                               unsigned ws_rule, int blank_at_eof)
 {
-       const char *set = diff_get_color(ecbdata->color_diff, color);
        const char *ws = NULL;
 
-       if (ecbdata->opt->ws_error_highlight & ws_error_highlight) {
-               ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
+       if (o->ws_error_highlight & ws_rule) {
+               ws = diff_get_color_opt(o, DIFF_WHITESPACE);
                if (!*ws)
                        ws = NULL;
        }
 
        if (!ws)
-               emit_line_0(ecbdata->opt, set, reset, sign, line, len);
-       else if (sign == '+' && new_blank_line_at_eof(ecbdata, line, len))
+               emit_line_0(o, set, reset, sign, line, len);
+       else if (blank_at_eof)
                /* Blank line at EOF - paint '+' as well */
-               emit_line_0(ecbdata->opt, ws, reset, sign, line, len);
+               emit_line_0(o, ws, reset, sign, line, len);
        else {
                /* Emit just the prefix, then the rest. */
-               emit_line_0(ecbdata->opt, set, reset, sign, "", 0);
-               ws_check_emit(line, len, ecbdata->ws_rule,
-                             ecbdata->opt->file, set, reset, ws);
+               emit_line_0(o, set, reset, sign, "", 0);
+               ws_check_emit(line, len, ws_rule,
+                             o->file, set, reset, ws);
+       }
+}
+
+static void emit_diff_symbol_from_struct(struct diff_options *o,
+                                        struct emitted_diff_symbol *eds)
+{
+       static const char *nneof = " No newline at end of file\n";
+       const char *context, *reset, *set, *meta, *fraginfo;
+       struct strbuf sb = STRBUF_INIT;
+
+       enum diff_symbol s = eds->s;
+       const char *line = eds->line;
+       int len = eds->len;
+       unsigned flags = eds->flags;
+
+       switch (s) {
+       case DIFF_SYMBOL_NO_LF_EOF:
+               context = diff_get_color_opt(o, DIFF_CONTEXT);
+               reset = diff_get_color_opt(o, DIFF_RESET);
+               putc('\n', o->file);
+               emit_line_0(o, context, reset, '\\',
+                           nneof, strlen(nneof));
+               break;
+       case DIFF_SYMBOL_SUBMODULE_HEADER:
+       case DIFF_SYMBOL_SUBMODULE_ERROR:
+       case DIFF_SYMBOL_SUBMODULE_PIPETHROUGH:
+       case DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES:
+       case DIFF_SYMBOL_SUMMARY:
+       case DIFF_SYMBOL_STATS_LINE:
+       case DIFF_SYMBOL_BINARY_DIFF_BODY:
+       case DIFF_SYMBOL_CONTEXT_FRAGINFO:
+               emit_line(o, "", "", line, len);
+               break;
+       case DIFF_SYMBOL_CONTEXT_INCOMPLETE:
+       case DIFF_SYMBOL_CONTEXT_MARKER:
+               context = diff_get_color_opt(o, DIFF_CONTEXT);
+               reset = diff_get_color_opt(o, DIFF_RESET);
+               emit_line(o, context, reset, line, len);
+               break;
+       case DIFF_SYMBOL_SEPARATOR:
+               fprintf(o->file, "%s%c",
+                       diff_line_prefix(o),
+                       o->line_termination);
+               break;
+       case DIFF_SYMBOL_CONTEXT:
+               set = diff_get_color_opt(o, DIFF_CONTEXT);
+               reset = diff_get_color_opt(o, DIFF_RESET);
+               emit_line_ws_markup(o, set, reset, line, len, ' ',
+                                   flags & (DIFF_SYMBOL_CONTENT_WS_MASK), 0);
+               break;
+       case DIFF_SYMBOL_PLUS:
+               switch (flags & (DIFF_SYMBOL_MOVED_LINE |
+                                DIFF_SYMBOL_MOVED_LINE_ALT |
+                                DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
+               case DIFF_SYMBOL_MOVED_LINE |
+                    DIFF_SYMBOL_MOVED_LINE_ALT |
+                    DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
+                       set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT_DIM);
+                       break;
+               case DIFF_SYMBOL_MOVED_LINE |
+                    DIFF_SYMBOL_MOVED_LINE_ALT:
+                       set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_ALT);
+                       break;
+               case DIFF_SYMBOL_MOVED_LINE |
+                    DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
+                       set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED_DIM);
+                       break;
+               case DIFF_SYMBOL_MOVED_LINE:
+                       set = diff_get_color_opt(o, DIFF_FILE_NEW_MOVED);
+                       break;
+               default:
+                       set = diff_get_color_opt(o, DIFF_FILE_NEW);
+               }
+               reset = diff_get_color_opt(o, DIFF_RESET);
+               emit_line_ws_markup(o, set, reset, line, len, '+',
+                                   flags & DIFF_SYMBOL_CONTENT_WS_MASK,
+                                   flags & DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF);
+               break;
+       case DIFF_SYMBOL_MINUS:
+               switch (flags & (DIFF_SYMBOL_MOVED_LINE |
+                                DIFF_SYMBOL_MOVED_LINE_ALT |
+                                DIFF_SYMBOL_MOVED_LINE_UNINTERESTING)) {
+               case DIFF_SYMBOL_MOVED_LINE |
+                    DIFF_SYMBOL_MOVED_LINE_ALT |
+                    DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
+                       set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT_DIM);
+                       break;
+               case DIFF_SYMBOL_MOVED_LINE |
+                    DIFF_SYMBOL_MOVED_LINE_ALT:
+                       set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_ALT);
+                       break;
+               case DIFF_SYMBOL_MOVED_LINE |
+                    DIFF_SYMBOL_MOVED_LINE_UNINTERESTING:
+                       set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED_DIM);
+                       break;
+               case DIFF_SYMBOL_MOVED_LINE:
+                       set = diff_get_color_opt(o, DIFF_FILE_OLD_MOVED);
+                       break;
+               default:
+                       set = diff_get_color_opt(o, DIFF_FILE_OLD);
+               }
+               reset = diff_get_color_opt(o, DIFF_RESET);
+               emit_line_ws_markup(o, set, reset, line, len, '-',
+                                   flags & DIFF_SYMBOL_CONTENT_WS_MASK, 0);
+               break;
+       case DIFF_SYMBOL_WORDS_PORCELAIN:
+               context = diff_get_color_opt(o, DIFF_CONTEXT);
+               reset = diff_get_color_opt(o, DIFF_RESET);
+               emit_line(o, context, reset, line, len);
+               fputs("~\n", o->file);
+               break;
+       case DIFF_SYMBOL_WORDS:
+               context = diff_get_color_opt(o, DIFF_CONTEXT);
+               reset = diff_get_color_opt(o, DIFF_RESET);
+               /*
+                * Skip the prefix character, if any.  With
+                * diff_suppress_blank_empty, there may be
+                * none.
+                */
+               if (line[0] != '\n') {
+                       line++;
+                       len--;
+               }
+               emit_line(o, context, reset, line, len);
+               break;
+       case DIFF_SYMBOL_FILEPAIR_PLUS:
+               meta = diff_get_color_opt(o, DIFF_METAINFO);
+               reset = diff_get_color_opt(o, DIFF_RESET);
+               fprintf(o->file, "%s%s+++ %s%s%s\n", diff_line_prefix(o), meta,
+                       line, reset,
+                       strchr(line, ' ') ? "\t" : "");
+               break;
+       case DIFF_SYMBOL_FILEPAIR_MINUS:
+               meta = diff_get_color_opt(o, DIFF_METAINFO);
+               reset = diff_get_color_opt(o, DIFF_RESET);
+               fprintf(o->file, "%s%s--- %s%s%s\n", diff_line_prefix(o), meta,
+                       line, reset,
+                       strchr(line, ' ') ? "\t" : "");
+               break;
+       case DIFF_SYMBOL_BINARY_FILES:
+       case DIFF_SYMBOL_HEADER:
+               fprintf(o->file, "%s", line);
+               break;
+       case DIFF_SYMBOL_BINARY_DIFF_HEADER:
+               fprintf(o->file, "%sGIT binary patch\n", diff_line_prefix(o));
+               break;
+       case DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA:
+               fprintf(o->file, "%sdelta %s\n", diff_line_prefix(o), line);
+               break;
+       case DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL:
+               fprintf(o->file, "%sliteral %s\n", diff_line_prefix(o), line);
+               break;
+       case DIFF_SYMBOL_BINARY_DIFF_FOOTER:
+               fputs(diff_line_prefix(o), o->file);
+               fputc('\n', o->file);
+               break;
+       case DIFF_SYMBOL_REWRITE_DIFF:
+               fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
+               reset = diff_get_color_opt(o, DIFF_RESET);
+               emit_line(o, fraginfo, reset, line, len);
+               break;
+       case DIFF_SYMBOL_SUBMODULE_ADD:
+               set = diff_get_color_opt(o, DIFF_FILE_NEW);
+               reset = diff_get_color_opt(o, DIFF_RESET);
+               emit_line(o, set, reset, line, len);
+               break;
+       case DIFF_SYMBOL_SUBMODULE_DEL:
+               set = diff_get_color_opt(o, DIFF_FILE_OLD);
+               reset = diff_get_color_opt(o, DIFF_RESET);
+               emit_line(o, set, reset, line, len);
+               break;
+       case DIFF_SYMBOL_SUBMODULE_UNTRACKED:
+               fprintf(o->file, "%sSubmodule %s contains untracked content\n",
+                       diff_line_prefix(o), line);
+               break;
+       case DIFF_SYMBOL_SUBMODULE_MODIFIED:
+               fprintf(o->file, "%sSubmodule %s contains modified content\n",
+                       diff_line_prefix(o), line);
+               break;
+       case DIFF_SYMBOL_STATS_SUMMARY_NO_FILES:
+               emit_line(o, "", "", " 0 files changed\n",
+                         strlen(" 0 files changed\n"));
+               break;
+       case DIFF_SYMBOL_STATS_SUMMARY_ABBREV:
+               emit_line(o, "", "", " ...\n", strlen(" ...\n"));
+               break;
+       case DIFF_SYMBOL_WORD_DIFF:
+               fprintf(o->file, "%.*s", len, line);
+               break;
+       case DIFF_SYMBOL_STAT_SEP:
+               fputs(o->stat_sep, o->file);
+               break;
+       default:
+               die("BUG: unknown diff symbol");
        }
+       strbuf_release(&sb);
+}
+
+static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
+                            const char *line, int len, unsigned flags)
+{
+       struct emitted_diff_symbol e = {line, len, flags, s};
+
+       if (o->emitted_symbols)
+               append_emitted_diff_symbol(o, &e);
+       else
+               emit_diff_symbol_from_struct(o, &e);
+}
+
+void diff_emit_submodule_del(struct diff_options *o, const char *line)
+{
+       emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_DEL, line, strlen(line), 0);
+}
+
+void diff_emit_submodule_add(struct diff_options *o, const char *line)
+{
+       emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ADD, line, strlen(line), 0);
+}
+
+void diff_emit_submodule_untracked(struct diff_options *o, const char *path)
+{
+       emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_UNTRACKED,
+                        path, strlen(path), 0);
+}
+
+void diff_emit_submodule_modified(struct diff_options *o, const char *path)
+{
+       emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_MODIFIED,
+                        path, strlen(path), 0);
+}
+
+void diff_emit_submodule_header(struct diff_options *o, const char *header)
+{
+       emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_HEADER,
+                        header, strlen(header), 0);
+}
+
+void diff_emit_submodule_error(struct diff_options *o, const char *err)
+{
+       emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_ERROR, err, strlen(err), 0);
+}
+
+void diff_emit_submodule_pipethrough(struct diff_options *o,
+                                    const char *line, int len)
+{
+       emit_diff_symbol(o, DIFF_SYMBOL_SUBMODULE_PIPETHROUGH, line, len, 0);
+}
+
+static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line, int len)
+{
+       if (!((ecbdata->ws_rule & WS_BLANK_AT_EOF) &&
+             ecbdata->blank_at_eof_in_preimage &&
+             ecbdata->blank_at_eof_in_postimage &&
+             ecbdata->blank_at_eof_in_preimage <= ecbdata->lno_in_preimage &&
+             ecbdata->blank_at_eof_in_postimage <= ecbdata->lno_in_postimage))
+               return 0;
+       return ws_blank_line(line, len, ecbdata->ws_rule);
 }
 
 static void emit_add_line(const char *reset,
                          struct emit_callback *ecbdata,
                          const char *line, int len)
 {
-       emit_line_checked(reset, ecbdata, line, len,
-                         DIFF_FILE_NEW, WSEH_NEW, '+');
+       unsigned flags = WSEH_NEW | ecbdata->ws_rule;
+       if (new_blank_line_at_eof(ecbdata, line, len))
+               flags |= DIFF_SYMBOL_CONTENT_BLANK_LINE_EOF;
+
+       emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_PLUS, line, len, flags);
 }
 
 static void emit_del_line(const char *reset,
                          struct emit_callback *ecbdata,
                          const char *line, int len)
 {
-       emit_line_checked(reset, ecbdata, line, len,
-                         DIFF_FILE_OLD, WSEH_OLD, '-');
+       unsigned flags = WSEH_OLD | ecbdata->ws_rule;
+       emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_MINUS, line, len, flags);
 }
 
 static void emit_context_line(const char *reset,
                              struct emit_callback *ecbdata,
                              const char *line, int len)
 {
-       emit_line_checked(reset, ecbdata, line, len,
-                         DIFF_CONTEXT, WSEH_CONTEXT, ' ');
+       unsigned flags = WSEH_CONTEXT | ecbdata->ws_rule;
+       emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_CONTEXT, line, len, flags);
 }
 
 static void emit_hunk_header(struct emit_callback *ecbdata,
@@ -576,7 +1363,8 @@ static void emit_hunk_header(struct emit_callback *ecbdata,
        if (len < 10 ||
            memcmp(line, atat, 2) ||
            !(ep = memmem(line + 2, len - 2, atat, 2))) {
-               emit_line(ecbdata->opt, context, reset, line, len);
+               emit_diff_symbol(ecbdata->opt,
+                                DIFF_SYMBOL_CONTEXT_MARKER, line, len, 0);
                return;
        }
        ep += 2; /* skip over @@ */
@@ -610,7 +1398,9 @@ static void emit_hunk_header(struct emit_callback *ecbdata,
        }
 
        strbuf_add(&msgbuf, line + len, org_len - len);
-       emit_line(ecbdata->opt, "", "", msgbuf.buf, msgbuf.len);
+       strbuf_complete_line(&msgbuf);
+       emit_diff_symbol(ecbdata->opt,
+                        DIFF_SYMBOL_CONTEXT_FRAGINFO, msgbuf.buf, msgbuf.len, 0);
        strbuf_release(&msgbuf);
 }
 
@@ -632,17 +1422,17 @@ static void remove_tempfile(void)
        }
 }
 
-static void print_line_count(FILE *file, int count)
+static void add_line_count(struct strbuf *out, int count)
 {
        switch (count) {
        case 0:
-               fprintf(file, "0,0");
+               strbuf_addstr(out, "0,0");
                break;
        case 1:
-               fprintf(file, "1");
+               strbuf_addstr(out, "1");
                break;
        default:
-               fprintf(file, "1,%d", count);
+               strbuf_addf(out, "1,%d", count);
                break;
        }
 }
@@ -651,7 +1441,6 @@ static void emit_rewrite_lines(struct emit_callback *ecb,
                               int prefix, const char *data, int size)
 {
        const char *endp = NULL;
-       static const char *nneof = " No newline at end of file\n";
        const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 
        while (0 < size) {
@@ -669,13 +1458,8 @@ static void emit_rewrite_lines(struct emit_callback *ecb,
                size -= len;
                data += len;
        }
-       if (!endp) {
-               const char *context = diff_get_color(ecb->color_diff,
-                                                    DIFF_CONTEXT);
-               putc('\n', ecb->opt->file);
-               emit_line_0(ecb->opt, context, reset, '\\',
-                           nneof, strlen(nneof));
-       }
+       if (!endp)
+               emit_diff_symbol(ecb->opt, DIFF_SYMBOL_NO_LF_EOF, NULL, 0, 0);
 }
 
 static void emit_rewrite_diff(const char *name_a,
@@ -687,16 +1471,12 @@ static void emit_rewrite_diff(const char *name_a,
                              struct diff_options *o)
 {
        int lc_a, lc_b;
-       const char *name_a_tab, *name_b_tab;
-       const char *metainfo = diff_get_color(o->use_color, DIFF_METAINFO);
-       const char *fraginfo = diff_get_color(o->use_color, DIFF_FRAGINFO);
-       const char *reset = diff_get_color(o->use_color, DIFF_RESET);
        static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
        const char *a_prefix, *b_prefix;
        char *data_one, *data_two;
        size_t size_one, size_two;
        struct emit_callback ecbdata;
-       const char *line_prefix = diff_line_prefix(o);
+       struct strbuf out = STRBUF_INIT;
 
        if (diff_mnemonic_prefix && DIFF_OPT_TST(o, REVERSE_DIFF)) {
                a_prefix = o->b_prefix;
@@ -708,8 +1488,6 @@ static void emit_rewrite_diff(const char *name_a,
 
        name_a += (*name_a == '/');
        name_b += (*name_b == '/');
-       name_a_tab = strchr(name_a, ' ') ? "\t" : "";
-       name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 
        strbuf_reset(&a_name);
        strbuf_reset(&b_name);
@@ -736,18 +1514,23 @@ static void emit_rewrite_diff(const char *name_a,
 
        lc_a = count_lines(data_one, size_one);
        lc_b = count_lines(data_two, size_two);
-       fprintf(o->file,
-               "%s%s--- %s%s%s\n%s%s+++ %s%s%s\n%s%s@@ -",
-               line_prefix, metainfo, a_name.buf, name_a_tab, reset,
-               line_prefix, metainfo, b_name.buf, name_b_tab, reset,
-               line_prefix, fraginfo);
+
+       emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
+                        a_name.buf, a_name.len, 0);
+       emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
+                        b_name.buf, b_name.len, 0);
+
+       strbuf_addstr(&out, "@@ -");
        if (!o->irreversible_delete)
-               print_line_count(o->file, lc_a);
+               add_line_count(&out, lc_a);
        else
-               fprintf(o->file, "?,?");
-       fprintf(o->file, " +");
-       print_line_count(o->file, lc_b);
-       fprintf(o->file, " @@%s\n", reset);
+               strbuf_addstr(&out, "?,?");
+       strbuf_addstr(&out, " +");
+       add_line_count(&out, lc_b);
+       strbuf_addstr(&out, " @@\n");
+       emit_diff_symbol(o, DIFF_SYMBOL_REWRITE_DIFF, out.buf, out.len, 0);
+       strbuf_release(&out);
+
        if (lc_a && !o->irreversible_delete)
                emit_rewrite_lines(&ecbdata, '-', data_one, size_one);
        if (lc_b)
@@ -807,44 +1590,56 @@ struct diff_words_data {
        struct diff_words_style *style;
 };
 
-static int fn_out_diff_words_write_helper(FILE *fp,
+static int fn_out_diff_words_write_helper(struct diff_options *o,
                                          struct diff_words_style_elem *st_el,
                                          const char *newline,
-                                         size_t count, const char *buf,
-                                         const char *line_prefix)
+                                         size_t count, const char *buf)
 {
        int print = 0;
+       struct strbuf sb = STRBUF_INIT;
 
        while (count) {
                char *p = memchr(buf, '\n', count);
                if (print)
-                       fputs(line_prefix, fp);
+                       strbuf_addstr(&sb, diff_line_prefix(o));
+
                if (p != buf) {
-                       if (st_el->color && fputs(st_el->color, fp) < 0)
-                               return -1;
-                       if (fputs(st_el->prefix, fp) < 0 ||
-                           fwrite(buf, p ? p - buf : count, 1, fp) != 1 ||
-                           fputs(st_el->suffix, fp) < 0)
-                               return -1;
-                       if (st_el->color && *st_el->color
-                           && fputs(GIT_COLOR_RESET, fp) < 0)
-                               return -1;
+                       const char *reset = st_el->color && *st_el->color ?
+                                           GIT_COLOR_RESET : NULL;
+                       if (st_el->color && *st_el->color)
+                               strbuf_addstr(&sb, st_el->color);
+                       strbuf_addstr(&sb, st_el->prefix);
+                       strbuf_add(&sb, buf, p ? p - buf : count);
+                       strbuf_addstr(&sb, st_el->suffix);
+                       if (reset)
+                               strbuf_addstr(&sb, reset);
                }
                if (!p)
-                       return 0;
-               if (fputs(newline, fp) < 0)
-                       return -1;
+                       goto out;
+
+               strbuf_addstr(&sb, newline);
                count -= p + 1 - buf;
                buf = p + 1;
                print = 1;
+               if (count) {
+                       emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
+                                        sb.buf, sb.len, 0);
+                       strbuf_reset(&sb);
+               }
        }
+
+out:
+       if (sb.len)
+               emit_diff_symbol(o, DIFF_SYMBOL_WORD_DIFF,
+                                sb.buf, sb.len, 0);
+       strbuf_release(&sb);
        return 0;
 }
 
 /*
  * '--color-words' algorithm can be described as:
  *
- *   1. collect the minus/plus lines of a diff hunk, divided into
+ *   1. collect the minus/plus lines of a diff hunk, divided into
  *      minus-lines and plus-lines;
  *
  *   2. break both minus-lines and plus-lines into words and
@@ -919,24 +1714,20 @@ static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
                fputs(line_prefix, diff_words->opt->file);
        }
        if (diff_words->current_plus != plus_begin) {
-               fn_out_diff_words_write_helper(diff_words->opt->file,
+               fn_out_diff_words_write_helper(diff_words->opt,
                                &style->ctx, style->newline,
                                plus_begin - diff_words->current_plus,
-                               diff_words->current_plus, line_prefix);
-               if (*(plus_begin - 1) == '\n')
-                       fputs(line_prefix, diff_words->opt->file);
+                               diff_words->current_plus);
        }
        if (minus_begin != minus_end) {
-               fn_out_diff_words_write_helper(diff_words->opt->file,
+               fn_out_diff_words_write_helper(diff_words->opt,
                                &style->old, style->newline,
-                               minus_end - minus_begin, minus_begin,
-                               line_prefix);
+                               minus_end - minus_begin, minus_begin);
        }
        if (plus_begin != plus_end) {
-               fn_out_diff_words_write_helper(diff_words->opt->file,
+               fn_out_diff_words_write_helper(diff_words->opt,
                                &style->new, style->newline,
-                               plus_end - plus_begin, plus_begin,
-                               line_prefix);
+                               plus_end - plus_begin, plus_begin);
        }
 
        diff_words->current_plus = plus_end;
@@ -1030,11 +1821,12 @@ static void diff_words_show(struct diff_words_data *diff_words)
 
        /* special case: only removal */
        if (!diff_words->plus.text.size) {
-               fputs(line_prefix, diff_words->opt->file);
-               fn_out_diff_words_write_helper(diff_words->opt->file,
+               emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
+                                line_prefix, strlen(line_prefix), 0);
+               fn_out_diff_words_write_helper(diff_words->opt,
                        &style->old, style->newline,
                        diff_words->minus.text.size,
-                       diff_words->minus.text.ptr, line_prefix);
+                       diff_words->minus.text.ptr);
                diff_words->minus.text.size = 0;
                return;
        }
@@ -1057,12 +1849,12 @@ static void diff_words_show(struct diff_words_data *diff_words)
        if (diff_words->current_plus != diff_words->plus.text.ptr +
                        diff_words->plus.text.size) {
                if (color_words_output_graph_prefix(diff_words))
-                       fputs(line_prefix, diff_words->opt->file);
-               fn_out_diff_words_write_helper(diff_words->opt->file,
+                       emit_diff_symbol(diff_words->opt, DIFF_SYMBOL_WORD_DIFF,
+                                        line_prefix, strlen(line_prefix), 0);
+               fn_out_diff_words_write_helper(diff_words->opt,
                        &style->ctx, style->newline,
                        diff_words->plus.text.ptr + diff_words->plus.text.size
-                       - diff_words->current_plus, diff_words->current_plus,
-                       line_prefix);
+                       - diff_words->current_plus, diff_words->current_plus);
        }
        diff_words->minus.text.size = diff_words->plus.text.size = 0;
 }
@@ -1070,9 +1862,29 @@ static void diff_words_show(struct diff_words_data *diff_words)
 /* In "color-words" mode, show word-diff of words accumulated in the buffer */
 static void diff_words_flush(struct emit_callback *ecbdata)
 {
+       struct diff_options *wo = ecbdata->diff_words->opt;
+
        if (ecbdata->diff_words->minus.text.size ||
            ecbdata->diff_words->plus.text.size)
                diff_words_show(ecbdata->diff_words);
+
+       if (wo->emitted_symbols) {
+               struct diff_options *o = ecbdata->opt;
+               struct emitted_diff_symbols *wol = wo->emitted_symbols;
+               int i;
+
+               /*
+                * NEEDSWORK:
+                * Instead of appending each, concat all words to a line?
+                */
+               for (i = 0; i < wol->nr; i++)
+                       append_emitted_diff_symbol(o, &wol->buf[i]);
+
+               for (i = 0; i < wol->nr; i++)
+                       free((void *)wol->buf[i].line);
+
+               wol->nr = 0;
+       }
 }
 
 static void diff_filespec_load_driver(struct diff_filespec *one)
@@ -1108,6 +1920,11 @@ static void init_diff_words_data(struct emit_callback *ecbdata,
                xcalloc(1, sizeof(struct diff_words_data));
        ecbdata->diff_words->type = o->word_diff;
        ecbdata->diff_words->opt = o;
+
+       if (orig_opts->emitted_symbols)
+               o->emitted_symbols =
+                       xcalloc(1, sizeof(struct emitted_diff_symbols));
+
        if (!o->word_regex)
                o->word_regex = userdiff_word_regex(one);
        if (!o->word_regex)
@@ -1142,6 +1959,7 @@ static void free_diff_words_data(struct emit_callback *ecbdata)
 {
        if (ecbdata->diff_words) {
                diff_words_flush(ecbdata);
+               free (ecbdata->diff_words->opt->emitted_symbols);
                free (ecbdata->diff_words->opt);
                free (ecbdata->diff_words->minus.text.ptr);
                free (ecbdata->diff_words->minus.orig);
@@ -1151,8 +1969,7 @@ static void free_diff_words_data(struct emit_callback *ecbdata)
                        regfree(ecbdata->diff_words->word_regex);
                        free(ecbdata->diff_words->word_regex);
                }
-               free(ecbdata->diff_words);
-               ecbdata->diff_words = NULL;
+               FREE_AND_NULL(ecbdata->diff_words);
        }
 }
 
@@ -1179,8 +1996,6 @@ static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, u
        unsigned long allot;
        size_t l = len;
 
-       if (ecb->truncate)
-               return ecb->truncate(line, len);
        cp = line;
        allot = l;
        while (0 < l) {
@@ -1209,30 +2024,25 @@ static void find_lno(const char *line, struct emit_callback *ecbdata)
 static void fn_out_consume(void *priv, char *line, unsigned long len)
 {
        struct emit_callback *ecbdata = priv;
-       const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
-       const char *context = diff_get_color(ecbdata->color_diff, DIFF_CONTEXT);
        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
        struct diff_options *o = ecbdata->opt;
-       const char *line_prefix = diff_line_prefix(o);
 
        o->found_changes = 1;
 
        if (ecbdata->header) {
-               fprintf(o->file, "%s", ecbdata->header->buf);
+               emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
+                                ecbdata->header->buf, ecbdata->header->len, 0);
                strbuf_reset(ecbdata->header);
                ecbdata->header = NULL;
        }
 
        if (ecbdata->label_path[0]) {
-               const char *name_a_tab, *name_b_tab;
-
-               name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
-               name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
-
-               fprintf(o->file, "%s%s--- %s%s%s\n",
-                       line_prefix, meta, ecbdata->label_path[0], reset, name_a_tab);
-               fprintf(o->file, "%s%s+++ %s%s%s\n",
-                       line_prefix, meta, ecbdata->label_path[1], reset, name_b_tab);
+               emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_MINUS,
+                                ecbdata->label_path[0],
+                                strlen(ecbdata->label_path[0]), 0);
+               emit_diff_symbol(o, DIFF_SYMBOL_FILEPAIR_PLUS,
+                                ecbdata->label_path[1],
+                                strlen(ecbdata->label_path[1]), 0);
                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
        }
 
@@ -1248,12 +2058,13 @@ static void fn_out_consume(void *priv, char *line, unsigned long len)
                len = sane_truncate_line(ecbdata, line, len);
                find_lno(line, ecbdata);
                emit_hunk_header(ecbdata, line, len);
-               if (line[len-1] != '\n')
-                       putc('\n', o->file);
                return;
        }
 
        if (ecbdata->diff_words) {
+               enum diff_symbol s =
+                       ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN ?
+                       DIFF_SYMBOL_WORDS_PORCELAIN : DIFF_SYMBOL_WORDS;
                if (line[0] == '-') {
                        diff_words_append(line, len,
                                          &ecbdata->diff_words->minus);
@@ -1273,21 +2084,7 @@ static void fn_out_consume(void *priv, char *line, unsigned long len)
                        return;
                }
                diff_words_flush(ecbdata);
-               if (ecbdata->diff_words->type == DIFF_WORDS_PORCELAIN) {
-                       emit_line(o, context, reset, line, len);
-                       fputs("~\n", o->file);
-               } else {
-                       /*
-                        * Skip the prefix character, if any.  With
-                        * diff_suppress_blank_empty, there may be
-                        * none.
-                        */
-                       if (line[0] != '\n') {
-                             line++;
-                             len--;
-                       }
-                       emit_line(o, context, reset, line, len);
-               }
+               emit_diff_symbol(o, s, line, len, 0);
                return;
        }
 
@@ -1308,8 +2105,8 @@ static void fn_out_consume(void *priv, char *line, unsigned long len)
        default:
                /* incomplete line at the end */
                ecbdata->lno_in_preimage++;
-               emit_line(o, diff_get_color(ecbdata->color_diff, DIFF_CONTEXT),
-                         reset, line, len);
+               emit_diff_symbol(o, DIFF_SYMBOL_CONTEXT_INCOMPLETE,
+                                line, len, 0);
                break;
        }
 }
@@ -1454,20 +2251,14 @@ static int scale_linear(int it, int width, int max_change)
        return 1 + (it * (width - 1) / max_change);
 }
 
-static void show_name(FILE *file,
-                     const char *prefix, const char *name, int len)
-{
-       fprintf(file, " %s%-*s |", prefix, len, name);
-}
-
-static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
+static void show_graph(struct strbuf *out, char ch, int cnt,
+                      const char *set, const char *reset)
 {
        if (cnt <= 0)
                return;
-       fprintf(file, "%s", set);
-       while (cnt--)
-               putc(ch, file);
-       fprintf(file, "%s", reset);
+       strbuf_addstr(out, set);
+       strbuf_addchars(out, ch, cnt);
+       strbuf_addstr(out, reset);
 }
 
 static void fill_print_name(struct diffstat_file *file)
@@ -1491,14 +2282,16 @@ static void fill_print_name(struct diffstat_file *file)
        file->print_name = pname;
 }
 
-int print_stat_summary(FILE *fp, int files, int insertions, int deletions)
+static void print_stat_summary_inserts_deletes(struct diff_options *options,
+               int files, int insertions, int deletions)
 {
        struct strbuf sb = STRBUF_INIT;
-       int ret;
 
        if (!files) {
                assert(insertions == 0 && deletions == 0);
-               return fprintf(fp, "%s\n", " 0 files changed");
+               emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_NO_FILES,
+                                NULL, 0, 0);
+               return;
        }
 
        strbuf_addf(&sb,
@@ -1525,9 +2318,19 @@ int print_stat_summary(FILE *fp, int files, int insertions, int deletions)
                            deletions);
        }
        strbuf_addch(&sb, '\n');
-       ret = fputs(sb.buf, fp);
+       emit_diff_symbol(options, DIFF_SYMBOL_STATS_SUMMARY_INSERTS_DELETES,
+                        sb.buf, sb.len, 0);
        strbuf_release(&sb);
-       return ret;
+}
+
+void print_stat_summary(FILE *fp, int files,
+                       int insertions, int deletions)
+{
+       struct diff_options o;
+       memset(&o, 0, sizeof(o));
+       o.file = fp;
+
+       print_stat_summary_inserts_deletes(&o, files, insertions, deletions);
 }
 
 static void show_stats(struct diffstat_t *data, struct diff_options *options)
@@ -1537,13 +2340,13 @@ static void show_stats(struct diffstat_t *data, struct diff_options *options)
        int total_files = data->nr, count;
        int width, name_width, graph_width, number_width = 0, bin_width = 0;
        const char *reset, *add_c, *del_c;
-       const char *line_prefix = "";
        int extra_shown = 0;
+       const char *line_prefix = diff_line_prefix(options);
+       struct strbuf out = STRBUF_INIT;
 
        if (data->nr == 0)
                return;
 
-       line_prefix = diff_line_prefix(options);
        count = options->stat_count ? options->stat_count : data->nr;
 
        reset = diff_get_color_opt(options, DIFF_RESET);
@@ -1616,7 +2419,7 @@ static void show_stats(struct diffstat_t *data, struct diff_options *options)
         */
 
        if (options->stat_width == -1)
-               width = term_columns() - options->output_prefix_length;
+               width = term_columns() - strlen(line_prefix);
        else
                width = options->stat_width ? options->stat_width : 80;
        number_width = decimal_width(max_change) > number_width ?
@@ -1697,26 +2500,32 @@ static void show_stats(struct diffstat_t *data, struct diff_options *options)
                }
 
                if (file->is_binary) {
-                       fprintf(options->file, "%s", line_prefix);
-                       show_name(options->file, prefix, name, len);
-                       fprintf(options->file, " %*s", number_width, "Bin");
+                       strbuf_addf(&out, " %s%-*s |", prefix, len, name);
+                       strbuf_addf(&out, " %*s", number_width, "Bin");
                        if (!added && !deleted) {
-                               putc('\n', options->file);
+                               strbuf_addch(&out, '\n');
+                               emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
+                                                out.buf, out.len, 0);
+                               strbuf_reset(&out);
                                continue;
                        }
-                       fprintf(options->file, " %s%"PRIuMAX"%s",
+                       strbuf_addf(&out, " %s%"PRIuMAX"%s",
                                del_c, deleted, reset);
-                       fprintf(options->file, " -> ");
-                       fprintf(options->file, "%s%"PRIuMAX"%s",
+                       strbuf_addstr(&out, " -> ");
+                       strbuf_addf(&out, "%s%"PRIuMAX"%s",
                                add_c, added, reset);
-                       fprintf(options->file, " bytes");
-                       fprintf(options->file, "\n");
+                       strbuf_addstr(&out, " bytes\n");
+                       emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
+                                        out.buf, out.len, 0);
+                       strbuf_reset(&out);
                        continue;
                }
                else if (file->is_unmerged) {
-                       fprintf(options->file, "%s", line_prefix);
-                       show_name(options->file, prefix, name, len);
-                       fprintf(options->file, " Unmerged\n");
+                       strbuf_addf(&out, " %s%-*s |", prefix, len, name);
+                       strbuf_addstr(&out, " Unmerged\n");
+                       emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
+                                        out.buf, out.len, 0);
+                       strbuf_reset(&out);
                        continue;
                }
 
@@ -1739,14 +2548,16 @@ static void show_stats(struct diffstat_t *data, struct diff_options *options)
                                add = total - del;
                        }
                }
-               fprintf(options->file, "%s", line_prefix);
-               show_name(options->file, prefix, name, len);
-               fprintf(options->file, " %*"PRIuMAX"%s",
+               strbuf_addf(&out, " %s%-*s |", prefix, len, name);
+               strbuf_addf(&out, " %*"PRIuMAX"%s",
                        number_width, added + deleted,
                        added + deleted ? " " : "");
-               show_graph(options->file, '+', add, add_c, reset);
-               show_graph(options->file, '-', del, del_c, reset);
-               fprintf(options->file, "\n");
+               show_graph(&out, '+', add, add_c, reset);
+               show_graph(&out, '-', del, del_c, reset);
+               strbuf_addch(&out, '\n');
+               emit_diff_symbol(options, DIFF_SYMBOL_STATS_LINE,
+                                out.buf, out.len, 0);
+               strbuf_reset(&out);
        }
 
        for (i = 0; i < data->nr; i++) {
@@ -1767,11 +2578,13 @@ static void show_stats(struct diffstat_t *data, struct diff_options *options)
                if (i < count)
                        continue;
                if (!extra_shown)
-                       fprintf(options->file, "%s ...\n", line_prefix);
+                       emit_diff_symbol(options,
+                                        DIFF_SYMBOL_STATS_SUMMARY_ABBREV,
+                                        NULL, 0, 0);
                extra_shown = 1;
        }
-       fprintf(options->file, "%s", line_prefix);
-       print_stat_summary(options->file, total_files, adds, dels);
+
+       print_stat_summary_inserts_deletes(options, total_files, adds, dels);
 }
 
 static void show_shortstats(struct diffstat_t *data, struct diff_options *options)
@@ -1783,7 +2596,7 @@ static void show_shortstats(struct diffstat_t *data, struct diff_options *option
 
        for (i = 0; i < data->nr; i++) {
                int added = data->files[i]->added;
-               int deleted= data->files[i]->deleted;
+               int deleted = data->files[i]->deleted;
 
                if (data->files[i]->is_unmerged ||
                    (!data->files[i]->is_interesting && (added + deleted == 0))) {
@@ -1793,8 +2606,7 @@ static void show_shortstats(struct diffstat_t *data, struct diff_options *option
                        dels += deleted;
                }
        }
-       fprintf(options->file, "%s", diff_line_prefix(options));
-       print_stat_summary(options->file, total_files, adds, dels);
+       print_stat_summary_inserts_deletes(options, total_files, adds, dels);
 }
 
 static void show_numstat(struct diffstat_t *data, struct diff_options *options)
@@ -1997,7 +2809,7 @@ static void show_dirstat(struct diff_options *options)
                return;
 
        /* Show all directories with more than x% of the changes */
-       qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
+       QSORT(dir.files, dir.nr, dirstat_compare);
        gather_dirstat(options, &dir, changed, "", 0);
 }
 
@@ -2028,7 +2840,7 @@ static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *o
                         * bytes per "line".
                         * This is stupid and ugly, but very cheap...
                         */
-                       damage = (damage + 63) / 64;
+                       damage = DIV_ROUND_UP(damage, 64);
                ALLOC_GROW(dir.files, dir.nr + 1, dir.alloc);
                dir.files[dir.nr].name = file->name;
                dir.files[dir.nr].changed = damage;
@@ -2041,7 +2853,7 @@ static void show_dirstat_by_line(struct diffstat_t *data, struct diff_options *o
                return;
 
        /* Show all directories with more than x% of the changes */
-       qsort(dir.files, dir.nr, sizeof(dir.files[0]), dirstat_compare);
+       QSORT(dir.files, dir.nr, dirstat_compare);
        gather_dirstat(options, &dir, changed, "", 0);
 }
 
@@ -2158,8 +2970,8 @@ static unsigned char *deflate_it(char *data,
        return deflated;
 }
 
-static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two,
-                                 const char *prefix)
+static void emit_binary_diff_body(struct diff_options *o,
+                                 mmfile_t *one, mmfile_t *two)
 {
        void *cp;
        void *delta;
@@ -2188,13 +3000,18 @@ static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two,
        }
 
        if (delta && delta_size < deflate_size) {
-               fprintf(file, "%sdelta %lu\n", prefix, orig_size);
+               char *s = xstrfmt("%lu", orig_size);
+               emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_DELTA,
+                                s, strlen(s), 0);
+               free(s);
                free(deflated);
                data = delta;
                data_size = delta_size;
-       }
-       else {
-               fprintf(file, "%sliteral %lu\n", prefix, two->size);
+       } else {
+               char *s = xstrfmt("%lu", two->size);
+               emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER_LITERAL,
+                                s, strlen(s), 0);
+               free(s);
                free(delta);
                data = deflated;
                data_size = deflate_size;
@@ -2203,8 +3020,9 @@ static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two,
        /* emit data encoded in base85 */
        cp = data;
        while (data_size) {
+               int len;
                int bytes = (52 < data_size) ? 52 : data_size;
-               char line[70];
+               char line[71];
                data_size -= bytes;
                if (bytes <= 26)
                        line[0] = bytes + 'A' - 1;
@@ -2212,20 +3030,24 @@ static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two,
                        line[0] = bytes - 26 + 'a' - 1;
                encode_85(line + 1, cp, bytes);
                cp = (char *) cp + bytes;
-               fprintf(file, "%s", prefix);
-               fputs(line, file);
-               fputc('\n', file);
+
+               len = strlen(line);
+               line[len++] = '\n';
+               line[len] = '\0';
+
+               emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_BODY,
+                                line, len, 0);
        }
-       fprintf(file, "%s\n", prefix);
+       emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_FOOTER, NULL, 0, 0);
        free(data);
 }
 
-static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two,
-                            const char *prefix)
+static void emit_binary_diff(struct diff_options *o,
+                            mmfile_t *one, mmfile_t *two)
 {
-       fprintf(file, "%sGIT binary patch\n", prefix);
-       emit_binary_diff_body(file, one, two, prefix);
-       emit_binary_diff_body(file, two, one, prefix);
+       emit_diff_symbol(o, DIFF_SYMBOL_BINARY_DIFF_HEADER, NULL, 0, 0);
+       emit_binary_diff_body(o, one, two);
+       emit_binary_diff_body(o, two, one);
 }
 
 int diff_filespec_is_binary(struct diff_filespec *one)
@@ -2290,24 +3112,6 @@ static void builtin_diff(const char *name_a,
        struct strbuf header = STRBUF_INIT;
        const char *line_prefix = diff_line_prefix(o);
 
-       if (DIFF_OPT_TST(o, SUBMODULE_LOG) &&
-                       (!one->mode || S_ISGITLINK(one->mode)) &&
-                       (!two->mode || S_ISGITLINK(two->mode))) {
-               const char *del = diff_get_color_opt(o, DIFF_FILE_OLD);
-               const char *add = diff_get_color_opt(o, DIFF_FILE_NEW);
-               show_submodule_summary(o->file, one->path ? one->path : two->path,
-                               line_prefix,
-                               one->oid.hash, two->oid.hash,
-                               two->dirty_submodule,
-                               meta, del, add, reset);
-               return;
-       }
-
-       if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
-               textconv_one = get_textconv(one);
-               textconv_two = get_textconv(two);
-       }
-
        diff_set_mnemonic_prefix(o, "a/", "b/");
        if (DIFF_OPT_TST(o, REVERSE_DIFF)) {
                a_prefix = o->b_prefix;
@@ -2317,6 +3121,27 @@ static void builtin_diff(const char *name_a,
                b_prefix = o->b_prefix;
        }
 
+       if (o->submodule_format == DIFF_SUBMODULE_LOG &&
+           (!one->mode || S_ISGITLINK(one->mode)) &&
+           (!two->mode || S_ISGITLINK(two->mode))) {
+               show_submodule_summary(o, one->path ? one->path : two->path,
+                               &one->oid, &two->oid,
+                               two->dirty_submodule);
+               return;
+       } else if (o->submodule_format == DIFF_SUBMODULE_INLINE_DIFF &&
+                  (!one->mode || S_ISGITLINK(one->mode)) &&
+                  (!two->mode || S_ISGITLINK(two->mode))) {
+               show_submodule_inline_diff(o, one->path ? one->path : two->path,
+                               &one->oid, &two->oid,
+                               two->dirty_submodule);
+               return;
+       }
+
+       if (DIFF_OPT_TST(o, ALLOW_TEXTCONV)) {
+               textconv_one = get_textconv(one);
+               textconv_two = get_textconv(two);
+       }
+
        /* Never use a non-valid filename anywhere if at all possible */
        name_a = DIFF_FILE_VALID(one) ? name_a : name_b;
        name_b = DIFF_FILE_VALID(two) ? name_b : name_a;
@@ -2357,7 +3182,8 @@ static void builtin_diff(const char *name_a,
                if (complete_rewrite &&
                    (textconv_one || !diff_filespec_is_binary(one)) &&
                    (textconv_two || !diff_filespec_is_binary(two))) {
-                       fprintf(o->file, "%s", header.buf);
+                       emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
+                                        header.buf, header.len, 0);
                        strbuf_reset(&header);
                        emit_rewrite_diff(name_a, name_b, one, two,
                                                textconv_one, textconv_two, o);
@@ -2367,23 +3193,31 @@ static void builtin_diff(const char *name_a,
        }
 
        if (o->irreversible_delete && lbl[1][0] == '/') {
-               fprintf(o->file, "%s", header.buf);
+               emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf,
+                                header.len, 0);
                strbuf_reset(&header);
                goto free_ab_and_return;
        } else if (!DIFF_OPT_TST(o, TEXT) &&
            ( (!textconv_one && diff_filespec_is_binary(one)) ||
              (!textconv_two && diff_filespec_is_binary(two)) )) {
+               struct strbuf sb = STRBUF_INIT;
                if (!one->data && !two->data &&
                    S_ISREG(one->mode) && S_ISREG(two->mode) &&
                    !DIFF_OPT_TST(o, BINARY)) {
                        if (!oidcmp(&one->oid, &two->oid)) {
                                if (must_show_header)
-                                       fprintf(o->file, "%s", header.buf);
+                                       emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
+                                                        header.buf, header.len,
+                                                        0);
                                goto free_ab_and_return;
                        }
-                       fprintf(o->file, "%s", header.buf);
-                       fprintf(o->file, "%sBinary files %s and %s differ\n",
-                               line_prefix, lbl[0], lbl[1]);
+                       emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
+                                        header.buf, header.len, 0);
+                       strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
+                                   diff_line_prefix(o), lbl[0], lbl[1]);
+                       emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
+                                        sb.buf, sb.len, 0);
+                       strbuf_release(&sb);
                        goto free_ab_and_return;
                }
                if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
@@ -2392,16 +3226,21 @@ static void builtin_diff(const char *name_a,
                if (mf1.size == mf2.size &&
                    !memcmp(mf1.ptr, mf2.ptr, mf1.size)) {
                        if (must_show_header)
-                               fprintf(o->file, "%s", header.buf);
+                               emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
+                                                header.buf, header.len, 0);
                        goto free_ab_and_return;
                }
-               fprintf(o->file, "%s", header.buf);
+               emit_diff_symbol(o, DIFF_SYMBOL_HEADER, header.buf, header.len, 0);
                strbuf_reset(&header);
                if (DIFF_OPT_TST(o, BINARY))
-                       emit_binary_diff(o->file, &mf1, &mf2, line_prefix);
-               else
-                       fprintf(o->file, "%sBinary files %s and %s differ\n",
-                               line_prefix, lbl[0], lbl[1]);
+                       emit_binary_diff(o, &mf1, &mf2);
+               else {
+                       strbuf_addf(&sb, "%sBinary files %s and %s differ\n",
+                                   diff_line_prefix(o), lbl[0], lbl[1]);
+                       emit_diff_symbol(o, DIFF_SYMBOL_BINARY_FILES,
+                                        sb.buf, sb.len, 0);
+                       strbuf_release(&sb);
+               }
                o->found_changes = 1;
        } else {
                /* Crazy xdl interfaces.. */
@@ -2413,7 +3252,8 @@ static void builtin_diff(const char *name_a,
                const struct userdiff_funcname *pe;
 
                if (must_show_header) {
-                       fprintf(o->file, "%s", header.buf);
+                       emit_diff_symbol(o, DIFF_SYMBOL_HEADER,
+                                        header.buf, header.len, 0);
                        strbuf_reset(&header);
                }
 
@@ -2624,13 +3464,13 @@ void free_filespec(struct diff_filespec *spec)
        }
 }
 
-void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
-                  int sha1_valid, unsigned short mode)
+void fill_filespec(struct diff_filespec *spec, const struct object_id *oid,
+                  int oid_valid, unsigned short mode)
 {
        if (mode) {
                spec->mode = canon_mode(mode);
-               hashcpy(spec->oid.hash, sha1);
-               spec->oid_valid = sha1_valid;
+               oidcpy(&spec->oid, oid);
+               spec->oid_valid = oid_valid;
        }
 }
 
@@ -2639,7 +3479,7 @@ void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
  * the work tree has that object contents, return true, so that
  * prepare_temp_file() does not have to inflate and extract.
  */
-static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
+static int reuse_worktree_file(const char *name, const struct object_id *oid, int want_file)
 {
        const struct cache_entry *ce;
        struct stat st;
@@ -2670,14 +3510,14 @@ static int reuse_worktree_file(const char *name, const unsigned char *sha1, int
         * objects however would tend to be slower as they need
         * to be individually opened and inflated.
         */
-       if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1))
+       if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(oid->hash))
                return 0;
 
        /*
         * Similarly, if we'd have to convert the file contents anyway, that
         * makes the optimization not worthwhile.
         */
-       if (!want_file && would_convert_to_git(name))
+       if (!want_file && would_convert_to_git(&the_index, name))
                return 0;
 
        len = strlen(name);
@@ -2690,7 +3530,7 @@ static int reuse_worktree_file(const char *name, const unsigned char *sha1, int
         * This is not the sha1 we are looking for, or
         * unreusable because it is not a regular file.
         */
-       if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
+       if (oidcmp(oid, &ce->oid) || !S_ISREG(ce->ce_mode))
                return 0;
 
        /*
@@ -2764,7 +3604,7 @@ int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
                return diff_populate_gitlink(s, size_only);
 
        if (!s->oid_valid ||
-           reuse_worktree_file(s->path, s->oid.hash, 0)) {
+           reuse_worktree_file(s->path, &s->oid, 0)) {
                struct strbuf buf = STRBUF_INIT;
                struct stat st;
                int fd;
@@ -2792,8 +3632,25 @@ int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
                        s->should_free = 1;
                        return 0;
                }
-               if (size_only)
+
+               /*
+                * Even if the caller would be happy with getting
+                * only the size, we cannot return early at this
+                * point if the path requires us to run the content
+                * conversion.
+                */
+               if (size_only && !would_convert_to_git(&the_index, s->path))
                        return 0;
+
+               /*
+                * Note: this check uses xsize_t(st.st_size) that may
+                * not be the true size of the blob after it goes
+                * through convert_to_git().  This may not strictly be
+                * correct, but the whole point of big_file_threshold
+                * and is_binary check being that we want to avoid
+                * opening the file and inspecting the contents, this
+                * is probably fine.
+                */
                if ((flags & CHECK_BINARY) &&
                    s->size > big_file_threshold && s->is_binary == -1) {
                        s->is_binary = 1;
@@ -2809,7 +3666,7 @@ int diff_populate_filespec(struct diff_filespec *s, unsigned int flags)
                /*
                 * Convert from working tree format to canonical git format
                 */
-               if (convert_to_git(s->path, s->data, s->size, &buf, crlf_warn)) {
+               if (convert_to_git(&the_index, s->path, s->data, s->size, &buf, crlf_warn)) {
                        size_t size = 0;
                        munmap(s->data, s->size);
                        s->should_munmap = 0;
@@ -2856,8 +3713,7 @@ void diff_free_filespec_blob(struct diff_filespec *s)
 void diff_free_filespec_data(struct diff_filespec *s)
 {
        diff_free_filespec_blob(s);
-       free(s->cnt_data);
-       s->cnt_data = NULL;
+       FREE_AND_NULL(s->cnt_data);
 }
 
 static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
@@ -2913,7 +3769,7 @@ static struct diff_tempfile *prepare_temp_file(const char *name,
 
        if (!S_ISGITLINK(one->mode) &&
            (!one->oid_valid ||
-            reuse_worktree_file(name, one->oid.hash, 1))) {
+            reuse_worktree_file(name, &one->oid, 1))) {
                struct stat st;
                if (lstat(name, &st) < 0) {
                        if (errno == ENOENT)
@@ -2935,13 +3791,13 @@ static struct diff_tempfile *prepare_temp_file(const char *name,
                        /* we can borrow from the file in the work tree */
                        temp->name = name;
                        if (!one->oid_valid)
-                               sha1_to_hex_r(temp->hex, null_sha1);
+                               oid_to_hex_r(temp->hex, &null_oid);
                        else
-                               sha1_to_hex_r(temp->hex, one->oid.hash);
+                               oid_to_hex_r(temp->hex, &one->oid);
                        /* Even though we may sometimes borrow the
                         * contents from the work tree, we always want
                         * one->mode.  mode is trustworthy even when
-                        * !(one->sha1_valid), as long as
+                        * !(one->oid_valid), as long as
                         * DIFF_FILE_VALID(one).
                         */
                        xsnprintf(temp->mode, sizeof(temp->mode), "%06o", one->mode);
@@ -3016,6 +3872,22 @@ static int similarity_index(struct diff_filepair *p)
        return p->score * 100 / MAX_SCORE;
 }
 
+static const char *diff_abbrev_oid(const struct object_id *oid, int abbrev)
+{
+       if (startup_info->have_repository)
+               return find_unique_abbrev(oid->hash, abbrev);
+       else {
+               char *hex = oid_to_hex(oid);
+               if (abbrev < 0)
+                       abbrev = FALLBACK_DEFAULT_ABBREV;
+               if (abbrev > GIT_SHA1_HEXSZ)
+                       die("BUG: oid abbreviation out of range: %d", abbrev);
+               if (abbrev)
+                       hex[abbrev] = '\0';
+               return hex;
+       }
+}
+
 static void fill_metainfo(struct strbuf *msg,
                          const char *name,
                          const char *other,
@@ -3074,9 +3946,9 @@ static void fill_metainfo(struct strbuf *msg,
                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
                                abbrev = 40;
                }
-               strbuf_addf(msg, "%s%sindex %s..", line_prefix, set,
-                           find_unique_abbrev(one->oid.hash, abbrev));
-               strbuf_add_unique_abbrev(msg, two->oid.hash, abbrev);
+               strbuf_addf(msg, "%s%sindex %s..%s", line_prefix, set,
+                           diff_abbrev_oid(&one->oid, abbrev),
+                           diff_abbrev_oid(&two->oid, abbrev));
                if (one->mode == two->mode)
                        strbuf_addf(msg, " %06o", one->mode);
                strbuf_addf(msg, "%s\n", reset);
@@ -3128,7 +4000,7 @@ static void run_diff_cmd(const char *pgm,
                fprintf(o->file, "* Unmerged path %s\n", name);
 }
 
-static void diff_fill_sha1_info(struct diff_filespec *one)
+static void diff_fill_oid_info(struct diff_filespec *one)
 {
        if (DIFF_FILE_VALID(one)) {
                if (!one->oid_valid) {
@@ -3172,8 +4044,8 @@ static void run_diff(struct diff_filepair *p, struct diff_options *o)
        const char *other;
        const char *attr_path;
 
-       name  = p->one->path;
-       other = (strcmp(name, p->two->path) ? p->two->path : NULL);
+       name  = one->path;
+       other = (strcmp(name, two->path) ? two->path : NULL);
        attr_path = name;
        if (o->prefix_length)
                strip_prefix(o->prefix_length, &name, &other);
@@ -3187,8 +4059,8 @@ static void run_diff(struct diff_filepair *p, struct diff_options *o)
                return;
        }
 
-       diff_fill_sha1_info(one);
-       diff_fill_sha1_info(two);
+       diff_fill_oid_info(one);
+       diff_fill_oid_info(two);
 
        if (!pgm &&
            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
@@ -3233,8 +4105,8 @@ static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
        if (o->prefix_length)
                strip_prefix(o->prefix_length, &name, &other);
 
-       diff_fill_sha1_info(p->one);
-       diff_fill_sha1_info(p->two);
+       diff_fill_oid_info(p->one);
+       diff_fill_oid_info(p->two);
 
        builtin_diffstat(name, other, p->one, p->two, diffstat, o, p);
 }
@@ -3257,8 +4129,8 @@ static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
        if (o->prefix_length)
                strip_prefix(o->prefix_length, &name, &other);
 
-       diff_fill_sha1_info(p->one);
-       diff_fill_sha1_info(p->two);
+       diff_fill_oid_info(p->one);
+       diff_fill_oid_info(p->two);
 
        builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
 }
@@ -3269,12 +4141,14 @@ void diff_setup(struct diff_options *options)
 
        options->file = stdout;
 
+       options->abbrev = DEFAULT_ABBREV;
        options->line_termination = '\n';
        options->break_opt = -1;
        options->rename_limit = -1;
        options->dirstat_permille = diff_dirstat_permille_default;
        options->context = diff_context_default;
-       options->ws_error_highlight = WSEH_NEW;
+       options->interhunkcontext = diff_interhunk_context_default;
+       options->ws_error_highlight = ws_error_highlight_default;
        DIFF_OPT_SET(options, RENAME_EMPTY);
 
        /* pathchange left =NULL by default */
@@ -3283,8 +4157,8 @@ void diff_setup(struct diff_options *options)
        options->use_color = diff_use_color_default;
        options->detect_rename = diff_detect_rename_default;
        options->xdl_opts |= diff_algorithm;
-       if (diff_compaction_heuristic)
-               DIFF_XDL_SET(options, COMPACTION_HEURISTIC);
+       if (diff_indent_heuristic)
+               DIFF_XDL_SET(options, INDENT_HEURISTIC);
 
        options->orderfile = diff_order_file_cfg;
 
@@ -3294,6 +4168,8 @@ void diff_setup(struct diff_options *options)
                options->a_prefix = "a/";
                options->b_prefix = "b/";
        }
+
+       options->color_moved = diff_color_moved_default;
 }
 
 void diff_setup_done(struct diff_options *options)
@@ -3312,7 +4188,7 @@ void diff_setup_done(struct diff_options *options)
        if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
                count++;
        if (count > 1)
-               die("--name-only, --name-status, --check and -s are mutually exclusive");
+               die(_("--name-only, --name-status, --check and -s are mutually exclusive"));
 
        /*
         * Most of the time we can say "there are changes"
@@ -3386,7 +4262,7 @@ void diff_setup_done(struct diff_options *options)
                         */
                        read_cache();
        }
-       if (options->abbrev <= 0 || 40 < options->abbrev)
+       if (40 < options->abbrev)
                options->abbrev = 40; /* full */
 
        /*
@@ -3403,6 +4279,9 @@ void diff_setup_done(struct diff_options *options)
 
        if (DIFF_OPT_TST(options, FOLLOW_RENAMES) && options->pathspec.nr != 1)
                die(_("--follow requires exactly one pathspec"));
+
+       if (!options->use_color || external_diff())
+               options->color_moved = 0;
 }
 
 static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
@@ -3508,7 +4387,7 @@ static int stat_opt(struct diff_options *options, const char **av)
                        if (*arg == '=')
                                width = strtoul(arg + 1, &end, 10);
                        else if (!*arg && !av[1])
-                               die("Option '--stat-width' requires a value");
+                               die_want_option("--stat-width");
                        else if (!*arg) {
                                width = strtoul(av[1], &end, 10);
                                argcount = 2;
@@ -3517,7 +4396,7 @@ static int stat_opt(struct diff_options *options, const char **av)
                        if (*arg == '=')
                                name_width = strtoul(arg + 1, &end, 10);
                        else if (!*arg && !av[1])
-                               die("Option '--stat-name-width' requires a value");
+                               die_want_option("--stat-name-width");
                        else if (!*arg) {
                                name_width = strtoul(av[1], &end, 10);
                                argcount = 2;
@@ -3526,7 +4405,7 @@ static int stat_opt(struct diff_options *options, const char **av)
                        if (*arg == '=')
                                graph_width = strtoul(arg + 1, &end, 10);
                        else if (!*arg && !av[1])
-                               die("Option '--stat-graph-width' requires a value");
+                               die_want_option("--stat-graph-width");
                        else if (!*arg) {
                                graph_width = strtoul(av[1], &end, 10);
                                argcount = 2;
@@ -3535,7 +4414,7 @@ static int stat_opt(struct diff_options *options, const char **av)
                        if (*arg == '=')
                                count = strtoul(arg + 1, &end, 10);
                        else if (!*arg && !av[1])
-                               die("Option '--stat-count' requires a value");
+                               die_want_option("--stat-count");
                        else if (!*arg) {
                                count = strtoul(av[1], &end, 10);
                                argcount = 2;
@@ -3663,40 +4542,14 @@ static void enable_patch_output(int *fmt) {
        *fmt |= DIFF_FORMAT_PATCH;
 }
 
-static int parse_one_token(const char **arg, const char *token)
+static int parse_ws_error_highlight_opt(struct diff_options *opt, const char *arg)
 {
-       const char *rest;
-       if (skip_prefix(*arg, token, &rest) && (!*rest || *rest == ',')) {
-               *arg = rest;
-               return 1;
-       }
-       return 0;
-}
+       int val = parse_ws_error_highlight(arg);
 
-static int parse_ws_error_highlight(struct diff_options *opt, const char *arg)
-{
-       const char *orig_arg = arg;
-       unsigned val = 0;
-       while (*arg) {
-               if (parse_one_token(&arg, "none"))
-                       val = 0;
-               else if (parse_one_token(&arg, "default"))
-                       val = WSEH_NEW;
-               else if (parse_one_token(&arg, "all"))
-                       val = WSEH_NEW | WSEH_OLD | WSEH_CONTEXT;
-               else if (parse_one_token(&arg, "new"))
-                       val |= WSEH_NEW;
-               else if (parse_one_token(&arg, "old"))
-                       val |= WSEH_OLD;
-               else if (parse_one_token(&arg, "context"))
-                       val |= WSEH_CONTEXT;
-               else {
-                       error("unknown value after ws-error-highlight=%.*s",
-                             (int)(arg - orig_arg), orig_arg);
-                       return 0;
-               }
-               if (*arg)
-                       arg++;
+       if (val < 0) {
+               error("unknown value after ws-error-highlight=%.*s",
+                     -1 - val, arg);
+               return 0;
        }
        opt->ws_error_highlight = val;
        return 1;
@@ -3805,10 +4658,10 @@ int diff_opt_parse(struct diff_options *options,
                DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
        else if (!strcmp(arg, "--ignore-blank-lines"))
                DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
-       else if (!strcmp(arg, "--compaction-heuristic"))
-               DIFF_XDL_SET(options, COMPACTION_HEURISTIC);
-       else if (!strcmp(arg, "--no-compaction-heuristic"))
-               DIFF_XDL_CLR(options, COMPACTION_HEURISTIC);
+       else if (!strcmp(arg, "--indent-heuristic"))
+               DIFF_XDL_SET(options, INDENT_HEURISTIC);
+       else if (!strcmp(arg, "--no-indent-heuristic"))
+               DIFF_XDL_CLR(options, INDENT_HEURISTIC);
        else if (!strcmp(arg, "--patience"))
                options->xdl_opts = DIFF_WITH_ALG(options, PATIENCE_DIFF);
        else if (!strcmp(arg, "--histogram"))
@@ -3853,7 +4706,19 @@ int diff_opt_parse(struct diff_options *options,
        }
        else if (!strcmp(arg, "--no-color"))
                options->use_color = 0;
-       else if (!strcmp(arg, "--color-words")) {
+       else if (!strcmp(arg, "--color-moved")) {
+               if (diff_color_moved_default)
+                       options->color_moved = diff_color_moved_default;
+               if (options->color_moved == COLOR_MOVED_NO)
+                       options->color_moved = COLOR_MOVED_DEFAULT;
+       } else if (!strcmp(arg, "--no-color-moved"))
+               options->color_moved = COLOR_MOVED_NO;
+       else if (skip_prefix(arg, "--color-moved=", &arg)) {
+               int cm = parse_color_moved(arg);
+               if (cm < 0)
+                       die("bad --color-moved argument: %s", arg);
+               options->color_moved = cm;
+       } else if (!strcmp(arg, "--color-words")) {
                options->use_color = 1;
                options->word_diff = DIFF_WORDS_COLOR;
        }
@@ -3905,11 +4770,15 @@ int diff_opt_parse(struct diff_options *options,
                DIFF_OPT_SET(options, OVERRIDE_SUBMODULE_CONFIG);
                handle_ignore_submodules_arg(options, arg);
        } else if (!strcmp(arg, "--submodule"))
-               DIFF_OPT_SET(options, SUBMODULE_LOG);
+               options->submodule_format = DIFF_SUBMODULE_LOG;
        else if (skip_prefix(arg, "--submodule=", &arg))
                return parse_submodule_opt(options, arg);
        else if (skip_prefix(arg, "--ws-error-highlight=", &arg))
-               return parse_ws_error_highlight(options, arg);
+               return parse_ws_error_highlight_opt(options, arg);
+       else if (!strcmp(arg, "--ita-invisible-in-index"))
+               options->ita_invisible_in_index = 1;
+       else if (!strcmp(arg, "--ita-visible-in-index"))
+               options->ita_invisible_in_index = 0;
 
        /* misc options */
        else if (!strcmp(arg, "-z"))
@@ -3932,8 +4801,7 @@ int diff_opt_parse(struct diff_options *options,
        else if (!strcmp(arg, "--pickaxe-regex"))
                options->pickaxe_opts |= DIFF_PICKAXE_REGEX;
        else if ((argcount = short_opt('O', av, &optarg))) {
-               const char *path = prefix_filename(prefix, strlen(prefix), optarg);
-               options->orderfile = xstrdup(path);
+               options->orderfile = prefix_filename(prefix, optarg);
                return argcount;
        }
        else if ((argcount = parse_long_opt("diff-filter", av, &optarg))) {
@@ -3943,6 +4811,8 @@ int diff_opt_parse(struct diff_options *options,
                            offending, optarg);
                return argcount;
        }
+       else if (!strcmp(arg, "--no-abbrev"))
+               options->abbrev = 0;
        else if (!strcmp(arg, "--abbrev"))
                options->abbrev = DEFAULT_ABBREV;
        else if (skip_prefix(arg, "--abbrev=", &arg)) {
@@ -3956,6 +4826,12 @@ int diff_opt_parse(struct diff_options *options,
                options->a_prefix = optarg;
                return argcount;
        }
+       else if ((argcount = parse_long_opt("line-prefix", av, &optarg))) {
+               options->line_prefix = optarg;
+               options->line_prefix_length = strlen(options->line_prefix);
+               graph_setup_line_prefix(options);
+               return argcount;
+       }
        else if ((argcount = parse_long_opt("dst-prefix", av, &optarg))) {
                options->b_prefix = optarg;
                return argcount;
@@ -3972,13 +4848,12 @@ int diff_opt_parse(struct diff_options *options,
        else if (!strcmp(arg, "--no-function-context"))
                DIFF_OPT_CLR(options, FUNCCONTEXT);
        else if ((argcount = parse_long_opt("output", av, &optarg))) {
-               const char *path = prefix_filename(prefix, strlen(prefix), optarg);
-               options->file = fopen(path, "w");
-               if (!options->file)
-                       die_errno("Could not open '%s'", path);
+               char *path = prefix_filename(prefix, optarg);
+               options->file = xfopen(path, "w");
                options->close_file = 1;
                if (options->use_color != GIT_COLOR_ALWAYS)
                        options->use_color = GIT_COLOR_NEVER;
+               free(path);
                return argcount;
        } else
                return 0;
@@ -4089,18 +4964,15 @@ void diff_free_filepair(struct diff_filepair *p)
        free(p);
 }
 
-/*
- * This is different from find_unique_abbrev() in that
- * it stuffs the result with dots for alignment.
- */
-const char *diff_unique_abbrev(const unsigned char *sha1, int len)
+const char *diff_aligned_abbrev(const struct object_id *oid, int len)
 {
        int abblen;
        const char *abbrev;
-       if (len == 40)
-               return sha1_to_hex(sha1);
 
-       abbrev = find_unique_abbrev(sha1, len);
+       if (len == GIT_SHA1_HEXSZ)
+               return oid_to_hex(oid);
+
+       abbrev = diff_abbrev_oid(oid, len);
        abblen = strlen(abbrev);
 
        /*
@@ -4122,15 +4994,16 @@ const char *diff_unique_abbrev(const unsigned char *sha1, int len)
         * the automatic sizing is supposed to give abblen that ensures
         * uniqueness across all objects (statistically speaking).
         */
-       if (abblen < 37) {
-               static char hex[41];
+       if (abblen < GIT_SHA1_HEXSZ - 3) {
+               static char hex[GIT_MAX_HEXSZ + 1];
                if (len < abblen && abblen <= len + 2)
                        xsnprintf(hex, sizeof(hex), "%s%.*s", abbrev, len+3-abblen, "..");
                else
                        xsnprintf(hex, sizeof(hex), "%s...", abbrev);
                return hex;
        }
-       return sha1_to_hex(sha1);
+
+       return oid_to_hex(oid);
 }
 
 static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
@@ -4141,9 +5014,9 @@ static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
        fprintf(opt->file, "%s", diff_line_prefix(opt));
        if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
                fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
-                       diff_unique_abbrev(p->one->oid.hash, opt->abbrev));
+                       diff_aligned_abbrev(&p->one->oid, opt->abbrev));
                fprintf(opt->file, "%s ",
-                       diff_unique_abbrev(p->two->oid.hash, opt->abbrev));
+                       diff_aligned_abbrev(&p->two->oid, opt->abbrev));
        }
        if (p->score) {
                fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
@@ -4370,71 +5243,81 @@ static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
                name_a = p->two->path;
                name_b = NULL;
                strip_prefix(opt->prefix_length, &name_a, &name_b);
+               fprintf(opt->file, "%s", diff_line_prefix(opt));
                write_name_quoted(name_a, opt->file, opt->line_termination);
        }
 }
 
-static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
+static void show_file_mode_name(struct diff_options *opt, const char *newdelete, struct diff_filespec *fs)
 {
+       struct strbuf sb = STRBUF_INIT;
        if (fs->mode)
-               fprintf(file, " %s mode %06o ", newdelete, fs->mode);
+               strbuf_addf(&sb, " %s mode %06o ", newdelete, fs->mode);
        else
-               fprintf(file, " %s ", newdelete);
-       write_name_quoted(fs->path, file, '\n');
-}
+               strbuf_addf(&sb, " %s ", newdelete);
 
+       quote_c_style(fs->path, &sb, NULL, 0);
+       strbuf_addch(&sb, '\n');
+       emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
+                        sb.buf, sb.len, 0);
+       strbuf_release(&sb);
+}
 
-static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name,
-               const char *line_prefix)
+static void show_mode_change(struct diff_options *opt, struct diff_filepair *p,
+               int show_name)
 {
        if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
-               fprintf(file, "%s mode change %06o => %06o%c", line_prefix, p->one->mode,
-                       p->two->mode, show_name ? ' ' : '\n');
+               struct strbuf sb = STRBUF_INIT;
+               strbuf_addf(&sb, " mode change %06o => %06o",
+                           p->one->mode, p->two->mode);
                if (show_name) {
-                       write_name_quoted(p->two->path, file, '\n');
+                       strbuf_addch(&sb, ' ');
+                       quote_c_style(p->two->path, &sb, NULL, 0);
                }
+               emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
+                                sb.buf, sb.len, 0);
+               strbuf_release(&sb);
        }
 }
 
-static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p,
-                       const char *line_prefix)
+static void show_rename_copy(struct diff_options *opt, const char *renamecopy,
+               struct diff_filepair *p)
 {
+       struct strbuf sb = STRBUF_INIT;
        char *names = pprint_rename(p->one->path, p->two->path);
-
-       fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
+       strbuf_addf(&sb, " %s %s (%d%%)\n",
+                       renamecopy, names, similarity_index(p));
        free(names);
-       show_mode_change(file, p, 0, line_prefix);
+       emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
+                                sb.buf, sb.len, 0);
+       show_mode_change(opt, p, 0);
 }
 
 static void diff_summary(struct diff_options *opt, struct diff_filepair *p)
 {
-       FILE *file = opt->file;
-       const char *line_prefix = diff_line_prefix(opt);
-
        switch(p->status) {
        case DIFF_STATUS_DELETED:
-               fputs(line_prefix, file);
-               show_file_mode_name(file, "delete", p->one);
+               show_file_mode_name(opt, "delete", p->one);
                break;
        case DIFF_STATUS_ADDED:
-               fputs(line_prefix, file);
-               show_file_mode_name(file, "create", p->two);
+               show_file_mode_name(opt, "create", p->two);
                break;
        case DIFF_STATUS_COPIED:
-               fputs(line_prefix, file);
-               show_rename_copy(file, "copy", p, line_prefix);
+               show_rename_copy(opt, "copy", p);
                break;
        case DIFF_STATUS_RENAMED:
-               fputs(line_prefix, file);
-               show_rename_copy(file, "rename", p, line_prefix);
+               show_rename_copy(opt, "rename", p);
                break;
        default:
                if (p->score) {
-                       fprintf(file, "%s rewrite ", line_prefix);
-                       write_name_quoted(p->two->path, file, ' ');
-                       fprintf(file, "(%d%%)\n", similarity_index(p));
+                       struct strbuf sb = STRBUF_INIT;
+                       strbuf_addstr(&sb, " rewrite ");
+                       quote_c_style(p->two->path, &sb, NULL, 0);
+                       strbuf_addf(&sb, " (%d%%)\n", similarity_index(p));
+                       emit_diff_symbol(opt, DIFF_SYMBOL_SUMMARY,
+                                        sb.buf, sb.len, 0);
                }
-               show_mode_change(file, p, !p->score, line_prefix);
+               show_mode_change(opt, p, !p->score);
                break;
        }
 }
@@ -4472,14 +5355,26 @@ static void patch_id_consume(void *priv, char *line, unsigned long len)
        data->patchlen += new_len;
 }
 
+static void patch_id_add_string(git_SHA_CTX *ctx, const char *str)
+{
+       git_SHA1_Update(ctx, str, strlen(str));
+}
+
+static void patch_id_add_mode(git_SHA_CTX *ctx, unsigned mode)
+{
+       /* large enough for 2^32 in octal */
+       char buf[12];
+       int len = xsnprintf(buf, sizeof(buf), "%06o", mode);
+       git_SHA1_Update(ctx, buf, len);
+}
+
 /* returns 0 upon success, and writes result into sha1 */
-static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1, int diff_header_only)
+static int diff_get_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
 {
        struct diff_queue_struct *q = &diff_queued_diff;
        int i;
        git_SHA_CTX ctx;
        struct patch_id_t data;
-       char buffer[PATH_MAX * 4 + 20];
 
        git_SHA1_Init(&ctx);
        memset(&data, 0, sizeof(struct patch_id_t));
@@ -4506,41 +5401,35 @@ static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1,
                if (DIFF_PAIR_UNMERGED(p))
                        continue;
 
-               diff_fill_sha1_info(p->one);
-               diff_fill_sha1_info(p->two);
+               diff_fill_oid_info(p->one);
+               diff_fill_oid_info(p->two);
 
                len1 = remove_space(p->one->path, strlen(p->one->path));
                len2 = remove_space(p->two->path, strlen(p->two->path));
-               if (p->one->mode == 0)
-                       len1 = snprintf(buffer, sizeof(buffer),
-                                       "diff--gita/%.*sb/%.*s"
-                                       "newfilemode%06o"
-                                       "---/dev/null"
-                                       "+++b/%.*s",
-                                       len1, p->one->path,
-                                       len2, p->two->path,
-                                       p->two->mode,
-                                       len2, p->two->path);
-               else if (p->two->mode == 0)
-                       len1 = snprintf(buffer, sizeof(buffer),
-                                       "diff--gita/%.*sb/%.*s"
-                                       "deletedfilemode%06o"
-                                       "---a/%.*s"
-                                       "+++/dev/null",
-                                       len1, p->one->path,
-                                       len2, p->two->path,
-                                       p->one->mode,
-                                       len1, p->one->path);
-               else
-                       len1 = snprintf(buffer, sizeof(buffer),
-                                       "diff--gita/%.*sb/%.*s"
-                                       "---a/%.*s"
-                                       "+++b/%.*s",
-                                       len1, p->one->path,
-                                       len2, p->two->path,
-                                       len1, p->one->path,
-                                       len2, p->two->path);
-               git_SHA1_Update(&ctx, buffer, len1);
+               patch_id_add_string(&ctx, "diff--git");
+               patch_id_add_string(&ctx, "a/");
+               git_SHA1_Update(&ctx, p->one->path, len1);
+               patch_id_add_string(&ctx, "b/");
+               git_SHA1_Update(&ctx, p->two->path, len2);
+
+               if (p->one->mode == 0) {
+                       patch_id_add_string(&ctx, "newfilemode");
+                       patch_id_add_mode(&ctx, p->two->mode);
+                       patch_id_add_string(&ctx, "---/dev/null");
+                       patch_id_add_string(&ctx, "+++b/");
+                       git_SHA1_Update(&ctx, p->two->path, len2);
+               } else if (p->two->mode == 0) {
+                       patch_id_add_string(&ctx, "deletedfilemode");
+                       patch_id_add_mode(&ctx, p->one->mode);
+                       patch_id_add_string(&ctx, "---a/");
+                       git_SHA1_Update(&ctx, p->one->path, len1);
+                       patch_id_add_string(&ctx, "+++/dev/null");
+               } else {
+                       patch_id_add_string(&ctx, "---a/");
+                       git_SHA1_Update(&ctx, p->one->path, len1);
+                       patch_id_add_string(&ctx, "+++b/");
+                       git_SHA1_Update(&ctx, p->two->path, len2);
+               }
 
                if (diff_header_only)
                        continue;
@@ -4552,9 +5441,9 @@ static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1,
                if (diff_filespec_is_binary(p->one) ||
                    diff_filespec_is_binary(p->two)) {
                        git_SHA1_Update(&ctx, oid_to_hex(&p->one->oid),
-                                       40);
+                                       GIT_SHA1_HEXSZ);
                        git_SHA1_Update(&ctx, oid_to_hex(&p->two->oid),
-                                       40);
+                                       GIT_SHA1_HEXSZ);
                        continue;
                }
 
@@ -4567,15 +5456,15 @@ static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1,
                                     p->one->path);
        }
 
-       git_SHA1_Final(sha1, &ctx);
+       git_SHA1_Final(oid->hash, &ctx);
        return 0;
 }
 
-int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1, int diff_header_only)
+int diff_flush_patch_id(struct diff_options *options, struct object_id *oid, int diff_header_only)
 {
        struct diff_queue_struct *q = &diff_queued_diff;
        int i;
-       int result = diff_get_patch_id(options, sha1, diff_header_only);
+       int result = diff_get_patch_id(options, oid, diff_header_only);
 
        for (i = 0; i < q->nr; i++)
                diff_free_filepair(q->queue[i]);
@@ -4612,25 +5501,70 @@ static int is_summary_empty(const struct diff_queue_struct *q)
 }
 
 static const char rename_limit_warning[] =
-"inexact rename detection was skipped due to too many files.";
+N_("inexact rename detection was skipped due to too many files.");
 
 static const char degrade_cc_to_c_warning[] =
-"only found copies from modified paths due to too many files.";
+N_("only found copies from modified paths due to too many files.");
 
 static const char rename_limit_advice[] =
-"you may want to set your %s variable to at least "
-"%d and retry the command.";
+N_("you may want to set your %s variable to at least "
+   "%d and retry the command.");
 
 void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc)
 {
        if (degraded_cc)
-               warning(degrade_cc_to_c_warning);
+               warning(_(degrade_cc_to_c_warning));
        else if (needed)
-               warning(rename_limit_warning);
+               warning(_(rename_limit_warning));
        else
                return;
        if (0 < needed && needed < 32767)
-               warning(rename_limit_advice, varname, needed);
+               warning(_(rename_limit_advice), varname, needed);
+}
+
+static void diff_flush_patch_all_file_pairs(struct diff_options *o)
+{
+       int i;
+       static struct emitted_diff_symbols esm = EMITTED_DIFF_SYMBOLS_INIT;
+       struct diff_queue_struct *q = &diff_queued_diff;
+
+       if (WSEH_NEW & WS_RULE_MASK)
+               die("BUG: WS rules bit mask overlaps with diff symbol flags");
+
+       if (o->color_moved)
+               o->emitted_symbols = &esm;
+
+       for (i = 0; i < q->nr; i++) {
+               struct diff_filepair *p = q->queue[i];
+               if (check_pair_status(p))
+                       diff_flush_patch(p, o);
+       }
+
+       if (o->emitted_symbols) {
+               if (o->color_moved) {
+                       struct hashmap add_lines, del_lines;
+
+                       hashmap_init(&del_lines,
+                                    (hashmap_cmp_fn)moved_entry_cmp, o, 0);
+                       hashmap_init(&add_lines,
+                                    (hashmap_cmp_fn)moved_entry_cmp, o, 0);
+
+                       add_lines_to_move_detection(o, &add_lines, &del_lines);
+                       mark_color_as_moved(o, &add_lines, &del_lines);
+                       if (o->color_moved == COLOR_MOVED_ZEBRA_DIM)
+                               dim_moved_lines(o);
+
+                       hashmap_free(&add_lines, 0);
+                       hashmap_free(&del_lines, 0);
+               }
+
+               for (i = 0; i < esm.nr; i++)
+                       emit_diff_symbol_from_struct(o, &esm.buf[i]);
+
+               for (i = 0; i < esm.nr; i++)
+                       free((void *)esm.buf[i].line);
+       }
+       esm.nr = 0;
 }
 
 void diff_flush(struct diff_options *options)
@@ -4703,10 +5637,9 @@ void diff_flush(struct diff_options *options)
                 */
                if (options->close_file)
                        fclose(options->file);
-               options->file = fopen("/dev/null", "w");
-               if (!options->file)
-                       die_errno("Could not open /dev/null");
+               options->file = xfopen("/dev/null", "w");
                options->close_file = 1;
+               options->color_moved = 0;
                for (i = 0; i < q->nr; i++) {
                        struct diff_filepair *p = q->queue[i];
                        if (check_pair_status(p))
@@ -4718,20 +5651,14 @@ void diff_flush(struct diff_options *options)
 
        if (output_format & DIFF_FORMAT_PATCH) {
                if (separator) {
-                       fprintf(options->file, "%s%c",
-                               diff_line_prefix(options),
-                               options->line_termination);
-                       if (options->stat_sep) {
+                       emit_diff_symbol(options, DIFF_SYMBOL_SEPARATOR, NULL, 0, 0);
+                       if (options->stat_sep)
                                /* attach patch instead of inline */
-                               fputs(options->stat_sep, options->file);
-                       }
+                               emit_diff_symbol(options, DIFF_SYMBOL_STAT_SEP,
+                                                NULL, 0, 0);
                }
 
-               for (i = 0; i < q->nr; i++) {
-                       struct diff_filepair *p = q->queue[i];
-                       if (check_pair_status(p))
-                               diff_flush_patch(p, options);
-               }
+               diff_flush_patch_all_file_pairs(options);
        }
 
        if (output_format & DIFF_FORMAT_CALLBACK)
@@ -4897,7 +5824,7 @@ static int diffnamecmp(const void *a_, const void *b_)
 void diffcore_fix_diff_index(struct diff_options *options)
 {
        struct diff_queue_struct *q = &diff_queued_diff;
-       qsort(q->queue, q->nr, sizeof(q->queue[0]), diffnamecmp);
+       QSORT(q->queue, q->nr, diffnamecmp);
 }
 
 void diffcore_std(struct diff_options *options)
@@ -4977,8 +5904,8 @@ static int is_submodule_ignored(const char *path, struct diff_options *options)
 
 void diff_addremove(struct diff_options *options,
                    int addremove, unsigned mode,
-                   const unsigned char *sha1,
-                   int sha1_valid,
+                   const struct object_id *oid,
+                   int oid_valid,
                    const char *concatpath, unsigned dirty_submodule)
 {
        struct diff_filespec *one, *two;
@@ -5010,9 +5937,9 @@ void diff_addremove(struct diff_options *options,
        two = alloc_filespec(concatpath);
 
        if (addremove != '+')
-               fill_filespec(one, sha1, sha1_valid, mode);
+               fill_filespec(one, oid, oid_valid, mode);
        if (addremove != '-') {
-               fill_filespec(two, sha1, sha1_valid, mode);
+               fill_filespec(two, oid, oid_valid, mode);
                two->dirty_submodule = dirty_submodule;
        }
 
@@ -5023,9 +5950,9 @@ void diff_addremove(struct diff_options *options,
 
 void diff_change(struct diff_options *options,
                 unsigned old_mode, unsigned new_mode,
-                const unsigned char *old_sha1,
-                const unsigned char *new_sha1,
-                int old_sha1_valid, int new_sha1_valid,
+                const struct object_id *old_oid,
+                const struct object_id *new_oid,
+                int old_oid_valid, int new_oid_valid,
                 const char *concatpath,
                 unsigned old_dirty_submodule, unsigned new_dirty_submodule)
 {
@@ -5037,14 +5964,10 @@ void diff_change(struct diff_options *options,
                return;
 
        if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
-               unsigned tmp;
-               const unsigned char *tmp_c;
-               tmp = old_mode; old_mode = new_mode; new_mode = tmp;
-               tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
-               tmp = old_sha1_valid; old_sha1_valid = new_sha1_valid;
-                       new_sha1_valid = tmp;
-               tmp = old_dirty_submodule; old_dirty_submodule = new_dirty_submodule;
-                       new_dirty_submodule = tmp;
+               SWAP(old_mode, new_mode);
+               SWAP(old_oid, new_oid);
+               SWAP(old_oid_valid, new_oid_valid);
+               SWAP(old_dirty_submodule, new_dirty_submodule);
        }
 
        if (options->prefix &&
@@ -5053,8 +5976,8 @@ void diff_change(struct diff_options *options,
 
        one = alloc_filespec(concatpath);
        two = alloc_filespec(concatpath);
-       fill_filespec(one, old_sha1, old_sha1_valid, old_mode);
-       fill_filespec(two, new_sha1, new_sha1_valid, new_mode);
+       fill_filespec(one, old_oid, old_oid_valid, old_mode);
+       fill_filespec(two, new_oid, new_oid_valid, new_mode);
        one->dirty_submodule = old_dirty_submodule;
        two->dirty_submodule = new_dirty_submodule;
        p = diff_queue(&diff_queued_diff, one, two);
@@ -5144,7 +6067,7 @@ size_t fill_textconv(struct userdiff_driver *driver,
 
        if (driver->textconv_cache && df->oid_valid) {
                *outbuf = notes_cache_get(driver->textconv_cache,
-                                         df->oid.hash,
+                                         &df->oid,
                                          &size);
                if (*outbuf)
                        return size;
@@ -5156,7 +6079,7 @@ size_t fill_textconv(struct userdiff_driver *driver,
 
        if (driver->textconv_cache && df->oid_valid) {
                /* ignore errors, as we might be in a readonly repository */
-               notes_cache_put(driver->textconv_cache, df->oid.hash, *outbuf,
+               notes_cache_put(driver->textconv_cache, &df->oid, *outbuf,
                                size);
                /*
                 * we could save up changes and flush them all at the end,
@@ -5170,6 +6093,29 @@ size_t fill_textconv(struct userdiff_driver *driver,
        return size;
 }
 
+int textconv_object(const char *path,
+                   unsigned mode,
+                   const struct object_id *oid,
+                   int oid_valid,
+                   char **buf,
+                   unsigned long *buf_size)
+{
+       struct diff_filespec *df;
+       struct userdiff_driver *textconv;
+
+       df = alloc_filespec(path);
+       fill_filespec(df, oid, oid_valid, mode);
+       textconv = get_textconv(df);
+       if (!textconv) {
+               free_filespec(df);
+               return 0;
+       }
+
+       *buf_size = fill_textconv(textconv, df, buf);
+       free_filespec(df);
+       return 1;
+}
+
 void setup_diff_pager(struct diff_options *opt)
 {
        /*