get-tar-commit-id: parse comment record
[gitweb.git] / diff.c
diff --git a/diff.c b/diff.c
index b24f6825a1327595d144592ba375c386a53216c5..ec5c095199b3953cc74dabdfccf4536d4c6df831 100644 (file)
--- a/diff.c
+++ b/diff.c
@@ -174,6 +174,10 @@ static int parse_submodule_params(struct diff_options *options, const char *valu
                options->submodule_format = DIFF_SUBMODULE_SHORT;
        else if (!strcmp(value, "diff"))
                options->submodule_format = DIFF_SUBMODULE_INLINE_DIFF;
+       /*
+        * Please update $__git_diff_submodule_formats in
+        * git-completion.bash when you add new formats.
+        */
        else
                return -1;
        return 0;
@@ -200,6 +204,10 @@ long parse_algorithm_value(const char *value)
                return XDF_PATIENCE_DIFF;
        else if (!strcasecmp(value, "histogram"))
                return XDF_HISTOGRAM_DIFF;
+       /*
+        * Please update $__git_diff_algorithms in git-completion.bash
+        * when you add new algorithms.
+        */
        return -1;
 }
 
@@ -300,7 +308,9 @@ static unsigned parse_color_moved_ws(const char *arg)
                strbuf_addstr(&sb, i->string);
                strbuf_trim(&sb);
 
-               if (!strcmp(sb.buf, "ignore-space-change"))
+               if (!strcmp(sb.buf, "no"))
+                       ret = 0;
+               else if (!strcmp(sb.buf, "ignore-space-change"))
                        ret |= XDF_IGNORE_WHITESPACE_CHANGE;
                else if (!strcmp(sb.buf, "ignore-space-at-eol"))
                        ret |= XDF_IGNORE_WHITESPACE_AT_EOL;
@@ -318,7 +328,7 @@ static unsigned parse_color_moved_ws(const char *arg)
 
        if ((ret & COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE) &&
            (ret & XDF_WHITESPACE_FLAGS)) {
-               error(_("color-moved-ws: allow-indentation-change cannot be combined with other white space modes"));
+               error(_("color-moved-ws: allow-indentation-change cannot be combined with other whitespace modes"));
                ret |= COLOR_MOVED_WS_ERROR;
        }
 
@@ -489,7 +499,7 @@ static const char *external_diff(void)
 
        if (done_preparing)
                return external_diff_cmd;
-       external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
+       external_diff_cmd = xstrdup_or_null(getenv("GIT_EXTERNAL_DIFF"));
        if (!external_diff_cmd)
                external_diff_cmd = external_diff_cmd_cfg;
        done_preparing = 1;
@@ -750,6 +760,8 @@ struct emitted_diff_symbol {
        const char *line;
        int len;
        int flags;
+       int indent_off;   /* Offset to first non-whitespace character */
+       int indent_width; /* The visual width of the indentation */
        enum diff_symbol s;
 };
 #define EMITTED_DIFF_SYMBOL_INIT {NULL}
@@ -780,44 +792,85 @@ struct moved_entry {
        struct moved_entry *next_line;
 };
 
-/**
- * The struct ws_delta holds white space differences between moved lines, i.e.
- * between '+' and '-' lines that have been detected to be a move.
- * The string contains the difference in leading white spaces, before the
- * rest of the line is compared using the white space config for move
- * coloring. The current_longer indicates if the first string in the
- * comparision is longer than the second.
- */
-struct ws_delta {
-       char *string;
-       unsigned int current_longer : 1;
-};
-#define WS_DELTA_INIT { NULL, 0 }
-
 struct moved_block {
        struct moved_entry *match;
-       struct ws_delta wsd;
+       int wsd; /* The whitespace delta of this block */
 };
 
 static void moved_block_clear(struct moved_block *b)
 {
-       FREE_AND_NULL(b->wsd.string);
-       b->match = NULL;
+       memset(b, 0, sizeof(*b));
 }
 
-static int compute_ws_delta(const struct emitted_diff_symbol *a,
-                            const struct emitted_diff_symbol *b,
-                            struct ws_delta *out)
+#define INDENT_BLANKLINE INT_MIN
+
+static void fill_es_indent_data(struct emitted_diff_symbol *es)
 {
-       const struct emitted_diff_symbol *longer =  a->len > b->len ? a : b;
-       const struct emitted_diff_symbol *shorter = a->len > b->len ? b : a;
-       int d = longer->len - shorter->len;
+       unsigned int off = 0, i;
+       int width = 0, tab_width = es->flags & WS_TAB_WIDTH_MASK;
+       const char *s = es->line;
+       const int len = es->len;
+
+       /* skip any \v \f \r at start of indentation */
+       while (s[off] == '\f' || s[off] == '\v' ||
+              (s[off] == '\r' && off < len - 1))
+               off++;
+
+       /* calculate the visual width of indentation */
+       while(1) {
+               if (s[off] == ' ') {
+                       width++;
+                       off++;
+               } else if (s[off] == '\t') {
+                       width += tab_width - (width % tab_width);
+                       while (s[++off] == '\t')
+                               width += tab_width;
+               } else {
+                       break;
+               }
+       }
+
+       /* check if this line is blank */
+       for (i = off; i < len; i++)
+               if (!isspace(s[i]))
+                   break;
+
+       if (i == len) {
+               es->indent_width = INDENT_BLANKLINE;
+               es->indent_off = len;
+       } else {
+               es->indent_off = off;
+               es->indent_width = width;
+       }
+}
+
+static int compute_ws_delta(const struct emitted_diff_symbol *a,
+                           const struct emitted_diff_symbol *b,
+                           int *out)
+{
+       int a_len = a->len,
+           b_len = b->len,
+           a_off = a->indent_off,
+           a_width = a->indent_width,
+           b_off = b->indent_off,
+           b_width = b->indent_width;
+       int delta;
+
+       if (a_width == INDENT_BLANKLINE && b_width == INDENT_BLANKLINE) {
+               *out = INDENT_BLANKLINE;
+               return 1;
+       }
+
+       if (a->s == DIFF_SYMBOL_PLUS)
+               delta = a_width - b_width;
+       else
+               delta = b_width - a_width;
 
-       if (strncmp(longer->line + d, shorter->line, shorter->len))
+       if (a_len - a_off != b_len - b_off ||
+           memcmp(a->line + a_off, b->line + b_off, a_len - a_off))
                return 0;
 
-       out->string = xmemdupz(longer->line, d);
-       out->current_longer = (a == longer);
+       *out = delta;
 
        return 1;
 }
@@ -829,51 +882,53 @@ static int cmp_in_block_with_wsd(const struct diff_options *o,
                                 int n)
 {
        struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
-       int al = cur->es->len, cl = l->len;
+       int al = cur->es->len, bl = match->es->len, cl = l->len;
        const char *a = cur->es->line,
                   *b = match->es->line,
                   *c = l->line;
-
-       int wslen;
+       int a_off = cur->es->indent_off,
+           a_width = cur->es->indent_width,
+           c_off = l->indent_off,
+           c_width = l->indent_width;
+       int delta;
 
        /*
-        * We need to check if 'cur' is equal to 'match'.
-        * As those are from the same (+/-) side, we do not need to adjust for
-        * indent changes. However these were found using fuzzy matching
-        * so we do have to check if they are equal.
+        * We need to check if 'cur' is equal to 'match'.  As those
+        * are from the same (+/-) side, we do not need to adjust for
+        * indent changes. However these were found using fuzzy
+        * matching so we do have to check if they are equal. Here we
+        * just check the lengths. We delay calling memcmp() to check
+        * the contents until later as if the length comparison for a
+        * and c fails we can avoid the call all together.
         */
-       if (strcmp(a, b))
+       if (al != bl)
                return 1;
 
-       if (!pmb->wsd.string)
-               /*
-                * The white space delta is not active? This can happen
-                * when we exit early in this function.
-                */
-               return 1;
+       /* If 'l' and 'cur' are both blank then they match. */
+       if (a_width == INDENT_BLANKLINE && c_width == INDENT_BLANKLINE)
+               return 0;
 
        /*
-        * The indent changes of the block are known and stored in
-        * pmb->wsd; however we need to check if the indent changes of the
-        * current line are still the same as before.
-        *
-        * To do so we need to compare 'l' to 'cur', adjusting the
-        * one of them for the white spaces, depending which was longer.
+        * The indent changes of the block are known and stored in pmb->wsd;
+        * however we need to check if the indent changes of the current line
+        * match those of the current block and that the text of 'l' and 'cur'
+        * after the indentation match.
         */
+       if (cur->es->s == DIFF_SYMBOL_PLUS)
+               delta = a_width - c_width;
+       else
+               delta = c_width - a_width;
 
-       wslen = strlen(pmb->wsd.string);
-       if (pmb->wsd.current_longer) {
-               c += wslen;
-               cl -= wslen;
-       } else {
-               a += wslen;
-               al -= wslen;
-       }
-
-       if (al != cl || memcmp(a, c, al))
-               return 1;
+       /*
+        * If the previous lines of this block were all blank then set its
+        * whitespace delta.
+        */
+       if (pmb->wsd == INDENT_BLANKLINE)
+               pmb->wsd = delta;
 
-       return 0;
+       return !(delta == pmb->wsd && al - a_off == cl - c_off &&
+                !memcmp(a, b, al) && !
+                memcmp(a + a_off, c + c_off, al - a_off));
 }
 
 static int moved_entry_cmp(const void *hashmap_cmp_fn_data,
@@ -939,6 +994,9 @@ static void add_lines_to_move_detection(struct diff_options *o,
                        continue;
                }
 
+               if (o->color_moved_ws_handling &
+                   COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
+                       fill_es_indent_data(&o->emitted_symbols->buf[n]);
                key = prepare_entry(o, n);
                if (prev_line && prev_line->es->s == o->emitted_symbols->buf[n].s)
                        prev_line->next_line = key;
@@ -1017,8 +1075,7 @@ static int shrink_potential_moved_blocks(struct moved_block *pmb,
 
                if (lp < pmb_nr && rp > -1 && lp < rp) {
                        pmb[lp] = pmb[rp];
-                       pmb[rp].match = NULL;
-                       pmb[rp].wsd.string = NULL;
+                       memset(&pmb[rp], 0, sizeof(pmb[rp]));
                        rp--;
                        lp++;
                }
@@ -1038,14 +1095,17 @@ static int shrink_potential_moved_blocks(struct moved_block *pmb,
  * The last block consists of the (n - block_length)'th line up to but not
  * including the nth line.
  *
+ * Returns 0 if the last block is empty or is unset by this function, non zero
+ * otherwise.
+ *
  * 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)
+static int 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;
+               return block_length;
        for (i = 1; i < block_length + 1; i++) {
                const char *c = o->emitted_symbols->buf[n - i].line;
                for (; *c; c++) {
@@ -1053,11 +1113,12 @@ static void adjust_last_block(struct diff_options *o, int n, int block_length)
                                continue;
                        alnum_count++;
                        if (alnum_count >= COLOR_MOVED_MIN_ALNUM_COUNT)
-                               return;
+                               return 1;
                }
        }
        for (i = 1; i < block_length + 1; i++)
                o->emitted_symbols->buf[n - i].flags &= ~DIFF_SYMBOL_MOVED_LINE;
+       return 0;
 }
 
 /* Find blocks of moved code, delegate actual coloring decision to helper */
@@ -1067,7 +1128,7 @@ static void mark_color_as_moved(struct diff_options *o,
 {
        struct moved_block *pmb = NULL; /* potentially moved blocks */
        int pmb_nr = 0, pmb_alloc = 0;
-       int n, flipped_block = 1, block_length = 0;
+       int n, flipped_block = 0, block_length = 0;
 
 
        for (n = 0; n < o->emitted_symbols->nr; n++) {
@@ -1075,6 +1136,7 @@ static void mark_color_as_moved(struct diff_options *o,
                struct moved_entry *key;
                struct moved_entry *match = NULL;
                struct emitted_diff_symbol *l = &o->emitted_symbols->buf[n];
+               enum diff_symbol last_symbol = 0;
 
                switch (l->s) {
                case DIFF_SYMBOL_PLUS:
@@ -1090,7 +1152,7 @@ static void mark_color_as_moved(struct diff_options *o,
                        free(key);
                        break;
                default:
-                       flipped_block = 1;
+                       flipped_block = 0;
                }
 
                if (!match) {
@@ -1101,13 +1163,16 @@ static void mark_color_as_moved(struct diff_options *o,
                                moved_block_clear(&pmb[i]);
                        pmb_nr = 0;
                        block_length = 0;
+                       flipped_block = 0;
+                       last_symbol = l->s;
                        continue;
                }
 
-               l->flags |= DIFF_SYMBOL_MOVED_LINE;
-
-               if (o->color_moved == COLOR_MOVED_PLAIN)
+               if (o->color_moved == COLOR_MOVED_PLAIN) {
+                       last_symbol = l->s;
+                       l->flags |= DIFF_SYMBOL_MOVED_LINE;
                        continue;
+               }
 
                if (o->color_moved_ws_handling &
                    COLOR_MOVED_WS_ALLOW_INDENTATION_CHANGE)
@@ -1130,21 +1195,27 @@ static void mark_color_as_moved(struct diff_options *o,
                                                             &pmb[pmb_nr].wsd))
                                                pmb[pmb_nr++].match = match;
                                } else {
-                                       pmb[pmb_nr].wsd.string = NULL;
+                                       pmb[pmb_nr].wsd = 0;
                                        pmb[pmb_nr++].match = match;
                                }
                        }
 
-                       flipped_block = (flipped_block + 1) % 2;
+                       if (adjust_last_block(o, n, block_length) &&
+                           pmb_nr && last_symbol != l->s)
+                               flipped_block = (flipped_block + 1) % 2;
+                       else
+                               flipped_block = 0;
 
-                       adjust_last_block(o, n, block_length);
                        block_length = 0;
                }
 
-               block_length++;
-
-               if (flipped_block && o->color_moved != COLOR_MOVED_BLOCKS)
-                       l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
+               if (pmb_nr) {
+                       block_length++;
+                       l->flags |= DIFF_SYMBOL_MOVED_LINE;
+                       if (flipped_block && o->color_moved != COLOR_MOVED_BLOCKS)
+                               l->flags |= DIFF_SYMBOL_MOVED_LINE_ALT;
+               }
+               last_symbol = l->s;
        }
        adjust_last_block(o, n, block_length);
 
@@ -1488,7 +1559,7 @@ static void emit_diff_symbol_from_struct(struct diff_options *o,
 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};
+       struct emitted_diff_symbol e = {line, len, flags, 0, 0, s};
 
        if (o->emitted_symbols)
                append_emitted_diff_symbol(o, &e);
@@ -1546,8 +1617,7 @@ static int new_blank_line_at_eof(struct emit_callback *ecbdata, const char *line
        return ws_blank_line(line, len, ecbdata->ws_rule);
 }
 
-static void emit_add_line(const char *reset,
-                         struct emit_callback *ecbdata,
+static void emit_add_line(struct emit_callback *ecbdata,
                          const char *line, int len)
 {
        unsigned flags = WSEH_NEW | ecbdata->ws_rule;
@@ -1557,16 +1627,14 @@ static void emit_add_line(const char *reset,
        emit_diff_symbol(ecbdata->opt, DIFF_SYMBOL_PLUS, line, len, flags);
 }
 
-static void emit_del_line(const char *reset,
-                         struct emit_callback *ecbdata,
+static void emit_del_line(struct emit_callback *ecbdata,
                          const char *line, int len)
 {
        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,
+static void emit_context_line(struct emit_callback *ecbdata,
                              const char *line, int len)
 {
        unsigned flags = WSEH_CONTEXT | ecbdata->ws_rule;
@@ -1675,7 +1743,6 @@ static void emit_rewrite_lines(struct emit_callback *ecb,
                               int prefix, const char *data, int size)
 {
        const char *endp = NULL;
-       const char *reset = diff_get_color(ecb->color_diff, DIFF_RESET);
 
        while (0 < size) {
                int len;
@@ -1684,10 +1751,10 @@ static void emit_rewrite_lines(struct emit_callback *ecb,
                len = endp ? (endp - data + 1) : size;
                if (prefix != '+') {
                        ecb->lno_in_preimage++;
-                       emit_del_line(reset, ecb, data, len);
+                       emit_del_line(ecb, data, len);
                } else {
                        ecb->lno_in_postimage++;
-                       emit_add_line(reset, ecb, data, len);
+                       emit_add_line(ecb, data, len);
                }
                size -= len;
                data += len;
@@ -2224,7 +2291,7 @@ const char *diff_line_prefix(struct diff_options *opt)
        return msgbuf->buf;
 }
 
-static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
+static unsigned long sane_truncate_line(char *line, unsigned long len)
 {
        const char *cp;
        unsigned long allot;
@@ -2258,7 +2325,6 @@ 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 *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
        struct diff_options *o = ecbdata->opt;
 
        o->found_changes = 1;
@@ -2289,7 +2355,7 @@ static void fn_out_consume(void *priv, char *line, unsigned long len)
        if (line[0] == '@') {
                if (ecbdata->diff_words)
                        diff_words_flush(ecbdata);
-               len = sane_truncate_line(ecbdata, line, len);
+               len = sane_truncate_line(line, len);
                find_lno(line, ecbdata);
                emit_hunk_header(ecbdata, line, len);
                return;
@@ -2325,16 +2391,16 @@ static void fn_out_consume(void *priv, char *line, unsigned long len)
        switch (line[0]) {
        case '+':
                ecbdata->lno_in_postimage++;
-               emit_add_line(reset, ecbdata, line + 1, len - 1);
+               emit_add_line(ecbdata, line + 1, len - 1);
                break;
        case '-':
                ecbdata->lno_in_preimage++;
-               emit_del_line(reset, ecbdata, line + 1, len - 1);
+               emit_del_line(ecbdata, line + 1, len - 1);
                break;
        case ' ':
                ecbdata->lno_in_postimage++;
                ecbdata->lno_in_preimage++;
-               emit_context_line(reset, ecbdata, line + 1, len - 1);
+               emit_context_line(ecbdata, line + 1, len - 1);
                break;
        default:
                /* incomplete line at the end */
@@ -3477,7 +3543,7 @@ static void builtin_diff(const char *name_a,
                o->found_changes = 1;
        } else {
                /* Crazy xdl interfaces.. */
-               const char *diffopts = getenv("GIT_DIFF_OPTS");
+               const char *diffopts;
                const char *v;
                xpparam_t xpp;
                xdemitconf_t xecfg;
@@ -3520,12 +3586,15 @@ static void builtin_diff(const char *name_a,
                        xecfg.flags |= XDL_EMIT_FUNCCONTEXT;
                if (pe)
                        xdiff_set_find_func(&xecfg, pe->pattern, pe->cflags);
+
+               diffopts = getenv("GIT_DIFF_OPTS");
                if (!diffopts)
                        ;
                else if (skip_prefix(diffopts, "--unified=", &v))
                        xecfg.ctxlen = strtoul(v, NULL, 10);
                else if (skip_prefix(diffopts, "-u", &v))
                        xecfg.ctxlen = strtoul(v, NULL, 10);
+
                if (o->word_diff)
                        init_diff_words_data(&ecbdata, o, one, two);
                if (xdi_diff_outf(&mf1, &mf2, NULL, fn_out_consume,
@@ -4113,7 +4182,6 @@ static void run_external_diff(const char *pgm,
                              struct diff_filespec *one,
                              struct diff_filespec *two,
                              const char *xfrm_msg,
-                             int complete_rewrite,
                              struct diff_options *o)
 {
        struct argv_array argv = ARGV_ARRAY_INIT;
@@ -4271,8 +4339,7 @@ static void run_diff_cmd(const char *pgm,
        }
 
        if (pgm) {
-               run_external_diff(pgm, name, other, one, two, xfrm_msg,
-                                 complete_rewrite, o);
+               run_external_diff(pgm, name, other, one, two, xfrm_msg, o);
                return;
        }
        if (one && two)
@@ -4617,8 +4684,6 @@ static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *va
        return 1;
 }
 
-static int diff_scoreopt_parse(const char *opt);
-
 static inline int short_opt(char opt, const char **argv,
                            const char **optarg)
 {
@@ -4841,6 +4906,43 @@ static int parse_objfind_opt(struct diff_options *opt, const char *arg)
        return 1;
 }
 
+static int diff_opt_break_rewrites(const struct option *opt,
+                                  const char *arg, int unset)
+{
+       int *break_opt = opt->value;
+       int opt1, opt2;
+
+       BUG_ON_OPT_NEG(unset);
+       if (!arg)
+               arg = "";
+       opt1 = parse_rename_score(&arg);
+       if (*arg == 0)
+               opt2 = 0;
+       else if (*arg != '/')
+               return error(_("%s expects <n>/<m> form"), opt->long_name);
+       else {
+               arg++;
+               opt2 = parse_rename_score(&arg);
+       }
+       if (*arg != 0)
+               return error(_("%s expects <n>/<m> form"), opt->long_name);
+       *break_opt = opt1 | (opt2 << 16);
+       return 0;
+}
+
+static int diff_opt_char(const struct option *opt,
+                        const char *arg, int unset)
+{
+       char *value = opt->value;
+
+       BUG_ON_OPT_NEG(unset);
+       if (arg[1])
+               return error(_("%s expects a character, got '%s'"),
+                            opt->long_name, arg);
+       *value = arg[0];
+       return 0;
+}
+
 static int diff_opt_compact_summary(const struct option *opt,
                                    const char *arg, int unset)
 {
@@ -4872,6 +4974,71 @@ static int diff_opt_dirstat(const struct option *opt,
        return 0;
 }
 
+static int diff_opt_find_copies(const struct option *opt,
+                               const char *arg, int unset)
+{
+       struct diff_options *options = opt->value;
+
+       BUG_ON_OPT_NEG(unset);
+       if (!arg)
+               arg = "";
+       options->rename_score = parse_rename_score(&arg);
+       if (*arg != 0)
+               return error(_("invalid argument to %s"), opt->long_name);
+
+       if (options->detect_rename == DIFF_DETECT_COPY)
+               options->flags.find_copies_harder = 1;
+       else
+               options->detect_rename = DIFF_DETECT_COPY;
+
+       return 0;
+}
+
+static int diff_opt_find_renames(const struct option *opt,
+                                const char *arg, int unset)
+{
+       struct diff_options *options = opt->value;
+
+       BUG_ON_OPT_NEG(unset);
+       if (!arg)
+               arg = "";
+       options->rename_score = parse_rename_score(&arg);
+       if (*arg != 0)
+               return error(_("invalid argument to %s"), opt->long_name);
+
+       options->detect_rename = DIFF_DETECT_RENAME;
+       return 0;
+}
+
+static enum parse_opt_result diff_opt_output(struct parse_opt_ctx_t *ctx,
+                                            const struct option *opt,
+                                            const char *arg, int unset)
+{
+       struct diff_options *options = opt->value;
+       char *path;
+
+       BUG_ON_OPT_NEG(unset);
+       path = prefix_filename(ctx->prefix, arg);
+       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 0;
+}
+
+static int diff_opt_relative(const struct option *opt,
+                            const char *arg, int unset)
+{
+       struct diff_options *options = opt->value;
+
+       BUG_ON_OPT_NEG(unset);
+       options->flags.relative_name = 1;
+       if (arg)
+               options->prefix = arg;
+       return 0;
+}
+
 static int diff_opt_unified(const struct option *opt,
                            const char *arg, int unset)
 {
@@ -4965,6 +5132,75 @@ static void prep_parse_options(struct diff_options *options)
                OPT_CALLBACK_F(0, "compact-summary", options, NULL,
                               N_("generate compact summary in diffstat"),
                               PARSE_OPT_NOARG, diff_opt_compact_summary),
+               OPT_CALLBACK_F(0, "output-indicator-new",
+                              &options->output_indicators[OUTPUT_INDICATOR_NEW],
+                              N_("<char>"),
+                              N_("specify the character to indicate a new line instead of '+'"),
+                              PARSE_OPT_NONEG, diff_opt_char),
+               OPT_CALLBACK_F(0, "output-indicator-old",
+                              &options->output_indicators[OUTPUT_INDICATOR_OLD],
+                              N_("<char>"),
+                              N_("specify the character to indicate an old line instead of '-'"),
+                              PARSE_OPT_NONEG, diff_opt_char),
+               OPT_CALLBACK_F(0, "output-indicator-context",
+                              &options->output_indicators[OUTPUT_INDICATOR_CONTEXT],
+                              N_("<char>"),
+                              N_("specify the character to indicate a context instead of ' '"),
+                              PARSE_OPT_NONEG, diff_opt_char),
+
+               OPT_GROUP(N_("Diff rename options")),
+               OPT_CALLBACK_F('B', "break-rewrites", &options->break_opt, N_("<n>[/<m>]"),
+                              N_("break complete rewrite changes into pairs of delete and create"),
+                              PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
+                              diff_opt_break_rewrites),
+               OPT_CALLBACK_F('M', "find-renames", options, N_("<n>"),
+                              N_("detect renames"),
+                              PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
+                              diff_opt_find_renames),
+               OPT_SET_INT_F('D', "irreversible-delete", &options->irreversible_delete,
+                             N_("omit the preimage for deletes"),
+                             1, PARSE_OPT_NONEG),
+               OPT_CALLBACK_F('C', "find-copies", options, N_("<n>"),
+                              N_("detect copies"),
+                              PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
+                              diff_opt_find_copies),
+               OPT_BOOL(0, "find-copies-harder", &options->flags.find_copies_harder,
+                        N_("use unmodified files as source to find copies")),
+               OPT_SET_INT_F(0, "no-renames", &options->detect_rename,
+                             N_("disable rename detection"),
+                             0, PARSE_OPT_NONEG),
+               OPT_BOOL(0, "rename-empty", &options->flags.rename_empty,
+                        N_("use empty blobs as rename source")),
+
+               OPT_GROUP(N_("Diff algorithm options")),
+               OPT_BIT(0, "minimal", &options->xdl_opts,
+                       N_("produce the smallest possible diff"),
+                       XDF_NEED_MINIMAL),
+               OPT_BIT_F('w', "ignore-all-space", &options->xdl_opts,
+                         N_("ignore whitespace when comparing lines"),
+                         XDF_IGNORE_WHITESPACE, PARSE_OPT_NONEG),
+               OPT_BIT_F('b', "ignore-space-change", &options->xdl_opts,
+                         N_("ignore changes in amount of whitespace"),
+                         XDF_IGNORE_WHITESPACE_CHANGE, PARSE_OPT_NONEG),
+               OPT_BIT_F(0, "ignore-space-at-eol", &options->xdl_opts,
+                         N_("ignore changes in whitespace at EOL"),
+                         XDF_IGNORE_WHITESPACE_AT_EOL, PARSE_OPT_NONEG),
+               OPT_BIT_F(0, "ignore-cr-at-eol", &options->xdl_opts,
+                         N_("ignore carrier-return at the end of line"),
+                         XDF_IGNORE_CR_AT_EOL, PARSE_OPT_NONEG),
+               OPT_BIT_F(0, "ignore-blank-lines", &options->xdl_opts,
+                         N_("ignore changes whose lines are all blank"),
+                         XDF_IGNORE_BLANK_LINES, PARSE_OPT_NONEG),
+
+               OPT_GROUP(N_("Diff other options")),
+               OPT_CALLBACK_F(0, "relative", options, N_("<prefix>"),
+                              N_("when run from subdir, exclude changes outside and show relative paths"),
+                              PARSE_OPT_NONEG | PARSE_OPT_OPTARG,
+                              diff_opt_relative),
+               { OPTION_CALLBACK, 0, "output", options, N_("<file>"),
+                 N_("Output to a specific file"),
+                 PARSE_OPT_NONEG, NULL, 0, diff_opt_output },
+
                OPT_END()
        };
 
@@ -4992,65 +5228,8 @@ int diff_opt_parse(struct diff_options *options,
        if (ac)
                return ac;
 
-       /* Output format options */
-       if (skip_prefix(arg, "--output-indicator-new=", &arg))
-               options->output_indicators[OUTPUT_INDICATOR_NEW] = arg[0];
-       else if (skip_prefix(arg, "--output-indicator-old=", &arg))
-               options->output_indicators[OUTPUT_INDICATOR_OLD] = arg[0];
-       else if (skip_prefix(arg, "--output-indicator-context=", &arg))
-               options->output_indicators[OUTPUT_INDICATOR_CONTEXT] = arg[0];
-
-       /* renames options */
-       else if (starts_with(arg, "-B") ||
-                skip_to_optional_arg(arg, "--break-rewrites", NULL)) {
-               if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
-                       return error("invalid argument to -B: %s", arg+2);
-       }
-       else if (starts_with(arg, "-M") ||
-                skip_to_optional_arg(arg, "--find-renames", NULL)) {
-               if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
-                       return error("invalid argument to -M: %s", arg+2);
-               options->detect_rename = DIFF_DETECT_RENAME;
-       }
-       else if (!strcmp(arg, "-D") || !strcmp(arg, "--irreversible-delete")) {
-               options->irreversible_delete = 1;
-       }
-       else if (starts_with(arg, "-C") ||
-                skip_to_optional_arg(arg, "--find-copies", NULL)) {
-               if (options->detect_rename == DIFF_DETECT_COPY)
-                       options->flags.find_copies_harder = 1;
-               if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
-                       return error("invalid argument to -C: %s", arg+2);
-               options->detect_rename = DIFF_DETECT_COPY;
-       }
-       else if (!strcmp(arg, "--no-renames"))
-               options->detect_rename = 0;
-       else if (!strcmp(arg, "--rename-empty"))
-               options->flags.rename_empty = 1;
-       else if (!strcmp(arg, "--no-rename-empty"))
-               options->flags.rename_empty = 0;
-       else if (skip_to_optional_arg_default(arg, "--relative", &arg, NULL)) {
-               options->flags.relative_name = 1;
-               if (arg)
-                       options->prefix = arg;
-       }
-
        /* xdiff options */
-       else if (!strcmp(arg, "--minimal"))
-               DIFF_XDL_SET(options, NEED_MINIMAL);
-       else if (!strcmp(arg, "--no-minimal"))
-               DIFF_XDL_CLR(options, NEED_MINIMAL);
-       else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
-               DIFF_XDL_SET(options, IGNORE_WHITESPACE);
-       else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
-               DIFF_XDL_SET(options, IGNORE_WHITESPACE_CHANGE);
-       else if (!strcmp(arg, "--ignore-space-at-eol"))
-               DIFF_XDL_SET(options, IGNORE_WHITESPACE_AT_EOL);
-       else if (!strcmp(arg, "--ignore-cr-at-eol"))
-               DIFF_XDL_SET(options, IGNORE_CR_AT_EOL);
-       else if (!strcmp(arg, "--ignore-blank-lines"))
-               DIFF_XDL_SET(options, IGNORE_BLANK_LINES);
-       else if (!strcmp(arg, "--indent-heuristic"))
+       if (!strcmp(arg, "--indent-heuristic"))
                DIFF_XDL_SET(options, INDENT_HEURISTIC);
        else if (!strcmp(arg, "--no-indent-heuristic"))
                DIFF_XDL_CLR(options, INDENT_HEURISTIC);
@@ -5095,8 +5274,6 @@ int diff_opt_parse(struct diff_options *options,
                options->flags.text = 1;
        else if (!strcmp(arg, "-R"))
                options->flags.reverse_diff = 1;
-       else if (!strcmp(arg, "--find-copies-harder"))
-               options->flags.find_copies_harder = 1;
        else if (!strcmp(arg, "--follow"))
                options->flags.follow_renames = 1;
        else if (!strcmp(arg, "--no-follow")) {
@@ -5122,6 +5299,8 @@ int diff_opt_parse(struct diff_options *options,
                if (cm < 0)
                        return error("bad --color-moved argument: %s", arg);
                options->color_moved = cm;
+       } else if (!strcmp(arg, "--no-color-moved-ws")) {
+               options->color_moved_ws_handling = 0;
        } else if (skip_prefix(arg, "--color-moved-ws=", &arg)) {
                unsigned cm = parse_color_moved_ws(arg);
                if (cm & COLOR_MOVED_WS_ERROR)
@@ -5242,15 +5421,7 @@ int diff_opt_parse(struct diff_options *options,
        else if (opt_arg(arg, '\0', "inter-hunk-context",
                         &options->interhunkcontext))
                ;
-       else if ((argcount = parse_long_opt("output", av, &optarg))) {
-               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
+       else
                return 0;
        return 1;
 }
@@ -5291,47 +5462,6 @@ int parse_rename_score(const char **cp_p)
        return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
 }
 
-static int diff_scoreopt_parse(const char *opt)
-{
-       int opt1, opt2, cmd;
-
-       if (*opt++ != '-')
-               return -1;
-       cmd = *opt++;
-       if (cmd == '-') {
-               /* convert the long-form arguments into short-form versions */
-               if (skip_prefix(opt, "break-rewrites", &opt)) {
-                       if (*opt == 0 || *opt++ == '=')
-                               cmd = 'B';
-               } else if (skip_prefix(opt, "find-copies", &opt)) {
-                       if (*opt == 0 || *opt++ == '=')
-                               cmd = 'C';
-               } else if (skip_prefix(opt, "find-renames", &opt)) {
-                       if (*opt == 0 || *opt++ == '=')
-                               cmd = 'M';
-               }
-       }
-       if (cmd != 'M' && cmd != 'C' && cmd != 'B')
-               return -1; /* that is not a -M, -C, or -B option */
-
-       opt1 = parse_rename_score(&opt);
-       if (cmd != 'B')
-               opt2 = 0;
-       else {
-               if (*opt == 0)
-                       opt2 = 0;
-               else if (*opt != '/')
-                       return -1; /* we expect -B80/99 or -B80 */
-               else {
-                       opt++;
-                       opt2 = parse_rename_score(&opt);
-               }
-       }
-       if (*opt != 0)
-               return -1;
-       return opt1 | (opt2 << 16);
-}
-
 struct diff_queue_struct diff_queued_diff;
 
 void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
@@ -5968,8 +6098,10 @@ static void diff_flush_patch_all_file_pairs(struct diff_options *o)
 
                for (i = 0; i < esm.nr; i++)
                        free((void *)esm.buf[i].line);
+               esm.nr = 0;
+
+               o->emitted_symbols = NULL;
        }
-       esm.nr = 0;
 }
 
 void diff_flush(struct diff_options *options)
@@ -6228,7 +6360,7 @@ static int diffnamecmp(const void *a_, const void *b_)
        return strcmp(name_a, name_b);
 }
 
-void diffcore_fix_diff_index(struct diff_options *options)
+void diffcore_fix_diff_index(void)
 {
        struct diff_queue_struct *q = &diff_queued_diff;
        QSORT(q->queue, q->nr, diffnamecmp);