builtin-reflog.c: don't install new reflog on write failure
[gitweb.git] / diff.c
diff --git a/diff.c b/diff.c
index a6aaaf7e5a91f3e5ad5f85341429c80a3452504e..76ba5f4afc162d6cbc31bfaa6cb1875a3975833e 100644 (file)
--- a/diff.c
+++ b/diff.c
@@ -10,6 +10,7 @@
 #include "color.h"
 #include "attr.h"
 #include "run-command.h"
+#include "utf8.h"
 
 #ifdef NO_FAST_WORKING_DIRECTORY
 #define FAST_WORKING_DIRECTORY 0
@@ -20,6 +21,7 @@
 static int diff_detect_rename_default;
 static int diff_rename_limit_default = 100;
 static int diff_use_color_default;
+static const char *external_diff_cmd_cfg;
 int diff_auto_refresh_index = 1;
 
 static char diff_colors[][COLOR_MAXLEN] = {
@@ -55,17 +57,9 @@ static int parse_diff_color_slot(const char *var, int ofs)
 static struct ll_diff_driver {
        const char *name;
        struct ll_diff_driver *next;
-       char *cmd;
+       const char *cmd;
 } *user_diff, **user_diff_tail;
 
-static void read_config_if_needed(void)
-{
-       if (!user_diff_tail) {
-               user_diff_tail = &user_diff;
-               git_config(git_diff_ui_config);
-       }
-}
-
 /*
  * Currently there is only "diff.<drivername>.command" variable;
  * because there are "diff.color.<slot>" variables, we are parsing
@@ -92,10 +86,7 @@ static int parse_lldiff_command(const char *var, const char *ep, const char *val
                user_diff_tail = &(drv->next);
        }
 
-       if (!value)
-               return error("%s: lacks value", var);
-       drv->cmd = strdup(value);
-       return 0;
+       return git_config_string(&(drv->cmd), var, value);
 }
 
 /*
@@ -146,7 +137,7 @@ int git_diff_ui_config(const char *var, const char *value)
                return 0;
        }
        if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
-               diff_use_color_default = git_config_colorbool(var, value);
+               diff_use_color_default = git_config_colorbool(var, value, -1);
                return 0;
        }
        if (!strcmp(var, "diff.renames")) {
@@ -163,22 +154,43 @@ int git_diff_ui_config(const char *var, const char *value)
                diff_auto_refresh_index = git_config_bool(var, value);
                return 0;
        }
+       if (!strcmp(var, "diff.external")) {
+               if (!value)
+                       return config_error_nonbool(var);
+               external_diff_cmd_cfg = xstrdup(value);
+               return 0;
+       }
        if (!prefixcmp(var, "diff.")) {
                const char *ep = strrchr(var, '.');
 
-               if (ep != var + 4) {
-                       if (!strcmp(ep, ".command"))
-                               return parse_lldiff_command(var, ep, value);
-                       if (!strcmp(ep, ".funcname"))
-                               return parse_funcname_pattern(var, ep, value);
-               }
+               if (ep != var + 4 && !strcmp(ep, ".command"))
+                       return parse_lldiff_command(var, ep, value);
        }
+
+       return git_diff_basic_config(var, value);
+}
+
+int git_diff_basic_config(const char *var, const char *value)
+{
        if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
                int slot = parse_diff_color_slot(var, 11);
+               if (!value)
+                       return config_error_nonbool(var);
                color_parse(value, var, diff_colors[slot]);
                return 0;
        }
 
+       if (!prefixcmp(var, "diff.")) {
+               const char *ep = strrchr(var, '.');
+               if (ep != var + 4) {
+                       if (!strcmp(ep, ".funcname")) {
+                               if (!value)
+                                       return config_error_nonbool(var);
+                               return parse_funcname_pattern(var, ep, value);
+                       }
+               }
+       }
+
        return git_default_config(var, value);
 }
 
@@ -209,6 +221,8 @@ static const char *external_diff(void)
        if (done_preparing)
                return external_diff_cmd;
        external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
+       if (!external_diff_cmd)
+               external_diff_cmd = external_diff_cmd_cfg;
        done_preparing = 1;
        return external_diff_cmd;
 }
@@ -258,8 +272,8 @@ static void print_line_count(int count)
        }
 }
 
-static void copy_file(int prefix, const char *data, int size,
-               const char *set, const char *reset)
+static void copy_file_with_prefix(int prefix, const char *data, int size,
+                                 const char *set, const char *reset)
 {
        int ch, nl_just_seen = 1;
        while (0 < size--) {
@@ -283,36 +297,43 @@ static void emit_rewrite_diff(const char *name_a,
                              const char *name_b,
                              struct diff_filespec *one,
                              struct diff_filespec *two,
-                             int color_diff)
+                             struct diff_options *o)
 {
        int lc_a, lc_b;
+       int color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
        const char *name_a_tab, *name_b_tab;
        const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
        const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
        const char *old = diff_get_color(color_diff, DIFF_FILE_OLD);
        const char *new = diff_get_color(color_diff, DIFF_FILE_NEW);
        const char *reset = diff_get_color(color_diff, DIFF_RESET);
+       static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 
        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);
+       quote_two_c_style(&a_name, o->a_prefix, name_a, 0);
+       quote_two_c_style(&b_name, o->b_prefix, name_b, 0);
+
        diff_populate_filespec(one, 0);
        diff_populate_filespec(two, 0);
        lc_a = count_lines(one->data, one->size);
        lc_b = count_lines(two->data, two->size);
-       printf("%s--- a/%s%s%s\n%s+++ b/%s%s%s\n%s@@ -",
-              metainfo, name_a, name_a_tab, reset,
-              metainfo, name_b, name_b_tab, reset, fraginfo);
+       printf("%s--- %s%s%s\n%s+++ %s%s%s\n%s@@ -",
+              metainfo, a_name.buf, name_a_tab, reset,
+              metainfo, b_name.buf, name_b_tab, reset, fraginfo);
        print_line_count(lc_a);
        printf(" +");
        print_line_count(lc_b);
        printf(" @@%s\n", reset);
        if (lc_a)
-               copy_file('-', one->data, one->size, old, reset);
+               copy_file_with_prefix('-', one->data, one->size, old, reset);
        if (lc_b)
-               copy_file('+', two->data, two->size, new, reset);
+               copy_file_with_prefix('+', two->data, two->size, new, reset);
 }
 
 static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
@@ -439,7 +460,7 @@ static void diff_words_show(struct diff_words_data *diff_words)
        ecb.outf = xdiff_outf;
        ecb.priv = diff_words;
        diff_words->xm.consume = fn_out_diff_words_aux;
-       xdl_diff(&minus, &plus, &xpp, &xecfg, &ecb);
+       xdi_diff(&minus, &plus, &xpp, &xecfg, &ecb);
 
        free(minus.ptr);
        free(plus.ptr);
@@ -451,9 +472,13 @@ static void diff_words_show(struct diff_words_data *diff_words)
        }
 }
 
+typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
+
 struct emit_callback {
        struct xdiff_emit_state xm;
        int nparents, color_diff;
+       unsigned ws_rule;
+       sane_truncate_fn truncate;
        const char **label_path;
        struct diff_words_data *diff_words;
        int *found_changesp;
@@ -485,75 +510,9 @@ const char *diff_get_color(int diff_use_color, enum color_diff ix)
 
 static void emit_line(const char *set, const char *reset, const char *line, int len)
 {
-       if (len > 0 && line[len-1] == '\n')
-               len--;
        fputs(set, stdout);
        fwrite(line, len, 1, stdout);
-       puts(reset);
-}
-
-static void emit_line_with_ws(int nparents,
-               const char *set, const char *reset, const char *ws,
-               const char *line, int len)
-{
-       int col0 = nparents;
-       int last_tab_in_indent = -1;
-       int last_space_in_indent = -1;
-       int i;
-       int tail = len;
-       int need_highlight_leading_space = 0;
-       /* The line is a newly added line.  Does it have funny leading
-        * whitespaces?  In indent, SP should never precede a TAB.
-        */
-       for (i = col0; i < len; i++) {
-               if (line[i] == '\t') {
-                       last_tab_in_indent = i;
-                       if (0 <= last_space_in_indent)
-                               need_highlight_leading_space = 1;
-               }
-               else if (line[i] == ' ')
-                       last_space_in_indent = i;
-               else
-                       break;
-       }
-       fputs(set, stdout);
-       fwrite(line, col0, 1, stdout);
        fputs(reset, stdout);
-       if (((i == len) || line[i] == '\n') && i != col0) {
-               /* The whole line was indent */
-               emit_line(ws, reset, line + col0, len - col0);
-               return;
-       }
-       i = col0;
-       if (need_highlight_leading_space) {
-               while (i < last_tab_in_indent) {
-                       if (line[i] == ' ') {
-                               fputs(ws, stdout);
-                               putchar(' ');
-                               fputs(reset, stdout);
-                       }
-                       else
-                               putchar(line[i]);
-                       i++;
-               }
-       }
-       tail = len - 1;
-       if (line[tail] == '\n' && i < tail)
-               tail--;
-       while (i < tail) {
-               if (!isspace(line[tail]))
-                       break;
-               tail--;
-       }
-       if ((i < tail && line[tail + 1] != '\n')) {
-               /* This has whitespace between tail+1..len */
-               fputs(set, stdout);
-               fwrite(line + i, tail - i + 1, 1, stdout);
-               fputs(reset, stdout);
-               emit_line(ws, reset, line + tail + 1, len - tail - 1);
-       }
-       else
-               emit_line(set, reset, line + i, len - i);
 }
 
 static void emit_add_line(const char *reset, struct emit_callback *ecbdata, const char *line, int len)
@@ -563,9 +522,31 @@ static void emit_add_line(const char *reset, struct emit_callback *ecbdata, cons
 
        if (!*ws)
                emit_line(set, reset, line, len);
-       else
-               emit_line_with_ws(ecbdata->nparents, set, reset, ws,
-                               line, len);
+       else {
+               /* Emit just the prefix, then the rest. */
+               emit_line(set, reset, line, ecbdata->nparents);
+               (void)check_and_emit_line(line + ecbdata->nparents,
+                   len - ecbdata->nparents, ecbdata->ws_rule,
+                   stdout, set, reset, ws);
+       }
+}
+
+static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
+{
+       const char *cp;
+       unsigned long allot;
+       size_t l = len;
+
+       if (ecb->truncate)
+               return ecb->truncate(line, len);
+       cp = line;
+       allot = l;
+       while (0 < l) {
+               (void) utf8_width(&cp, &l);
+               if (!cp)
+                       break; /* truncated in the middle? */
+       }
+       return allot - l;
 }
 
 static void fn_out_consume(void *priv, char *line, unsigned long len)
@@ -573,7 +554,8 @@ static void fn_out_consume(void *priv, char *line, unsigned long len)
        int i;
        int color;
        struct emit_callback *ecbdata = priv;
-       const char *set = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
+       const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
+       const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
        const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 
        *(ecbdata->found_changesp) = 1;
@@ -585,9 +567,9 @@ static void fn_out_consume(void *priv, char *line, unsigned long len)
                name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
 
                printf("%s--- %s%s%s\n",
-                      set, ecbdata->label_path[0], reset, name_a_tab);
+                      meta, ecbdata->label_path[0], reset, name_a_tab);
                printf("%s+++ %s%s%s\n",
-                      set, ecbdata->label_path[1], reset, name_b_tab);
+                      meta, ecbdata->label_path[1], reset, name_b_tab);
                ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
        }
 
@@ -598,13 +580,15 @@ static void fn_out_consume(void *priv, char *line, unsigned long len)
                ;
        if (2 <= i && i < len && line[i] == ' ') {
                ecbdata->nparents = i - 1;
+               len = sane_truncate_line(ecbdata, line, len);
                emit_line(diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO),
                          reset, line, len);
+               if (line[len-1] != '\n')
+                       putchar('\n');
                return;
        }
 
        if (len < ecbdata->nparents) {
-               set = reset;
                emit_line(reset, reset, line, len);
                return;
        }
@@ -628,7 +612,7 @@ static void fn_out_consume(void *priv, char *line, unsigned long len)
                        diff_words_show(ecbdata->diff_words);
                line++;
                len--;
-               emit_line(set, reset, line, len);
+               emit_line(plain, reset, line, len);
                return;
        }
        for (i = 0; i < ecbdata->nparents && len; i++) {
@@ -720,7 +704,9 @@ struct diffstat_t {
        int nr;
        int alloc;
        struct diffstat_file {
+               char *from_name;
                char *name;
+               char *print_name;
                unsigned is_unmerged:1;
                unsigned is_binary:1;
                unsigned is_renamed:1;
@@ -741,11 +727,14 @@ static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
        }
        diffstat->files[diffstat->nr++] = x;
        if (name_b) {
-               x->name = pprint_rename(name_a, name_b);
+               x->from_name = xstrdup(name_a);
+               x->name = xstrdup(name_b);
                x->is_renamed = 1;
        }
-       else
+       else {
+               x->from_name = NULL;
                x->name = xstrdup(name_a);
+       }
        return x;
 }
 
@@ -789,6 +778,28 @@ static void show_graph(char ch, int cnt, const char *set, const char *reset)
        printf("%s", reset);
 }
 
+static void fill_print_name(struct diffstat_file *file)
+{
+       char *pname;
+
+       if (file->print_name)
+               return;
+
+       if (!file->is_renamed) {
+               struct strbuf buf;
+               strbuf_init(&buf, 0);
+               if (quote_c_style(file->name, &buf, NULL, 0)) {
+                       pname = strbuf_detach(&buf, NULL);
+               } else {
+                       pname = file->name;
+                       strbuf_release(&buf);
+               }
+       } else {
+               pname = pprint_rename(file->from_name, file->name);
+       }
+       file->print_name = pname;
+}
+
 static void show_stats(struct diffstat_t* data, struct diff_options *options)
 {
        int i, len, add, del, total, adds = 0, dels = 0;
@@ -814,27 +825,16 @@ static void show_stats(struct diffstat_t* data, struct diff_options *options)
        }
 
        /* Find the longest filename and max number of changes */
-       reset = diff_get_color(options->color_diff, DIFF_RESET);
-       set = diff_get_color(options->color_diff, DIFF_PLAIN);
-       add_c = diff_get_color(options->color_diff, DIFF_FILE_NEW);
-       del_c = diff_get_color(options->color_diff, DIFF_FILE_OLD);
+       reset = diff_get_color_opt(options, DIFF_RESET);
+       set   = diff_get_color_opt(options, DIFF_PLAIN);
+       add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
+       del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
 
        for (i = 0; i < data->nr; i++) {
                struct diffstat_file *file = data->files[i];
                int change = file->added + file->deleted;
-
-               if (!file->is_renamed) {  /* renames are already quoted by pprint_rename */
-                       struct strbuf buf;
-                       strbuf_init(&buf, 0);
-                       if (quote_c_style(file->name, &buf, NULL, 0)) {
-                               free(file->name);
-                               file->name = strbuf_detach(&buf, NULL);
-                       } else {
-                               strbuf_release(&buf);
-                       }
-               }
-
-               len = strlen(file->name);
+               fill_print_name(file);
+               len = strlen(file->print_name);
                if (max_len < len)
                        max_len = len;
 
@@ -859,7 +859,7 @@ static void show_stats(struct diffstat_t* data, struct diff_options *options)
 
        for (i = 0; i < data->nr; i++) {
                const char *prefix = "";
-               char *name = data->files[i]->name;
+               char *name = data->files[i]->print_name;
                int added = data->files[i]->added;
                int deleted = data->files[i]->deleted;
                int name_len;
@@ -887,17 +887,17 @@ static void show_stats(struct diffstat_t* data, struct diff_options *options)
                        printf("%s%d%s", add_c, added, reset);
                        printf(" bytes");
                        printf("\n");
-                       goto free_diffstat_file;
+                       continue;
                }
                else if (data->files[i]->is_unmerged) {
                        show_name(prefix, name, len, reset, set);
                        printf("  Unmerged\n");
-                       goto free_diffstat_file;
+                       continue;
                }
                else if (!data->files[i]->is_renamed &&
                         (added + deleted == 0)) {
                        total_files--;
-                       goto free_diffstat_file;
+                       continue;
                }
 
                /*
@@ -919,11 +919,7 @@ static void show_stats(struct diffstat_t* data, struct diff_options *options)
                show_graph('+', add, add_c, reset);
                show_graph('-', del, del_c, reset);
                putchar('\n');
-       free_diffstat_file:
-               free(data->files[i]->name);
-               free(data->files[i]);
        }
-       free(data->files);
        printf("%s %d files changed, %d insertions(+), %d deletions(-)%s\n",
               set, total_files, adds, dels, reset);
 }
@@ -948,11 +944,7 @@ static void show_shortstats(struct diffstat_t* data)
                                dels += deleted;
                        }
                }
-               free(data->files[i]->name);
-               free(data->files[i]);
        }
-       free(data->files);
-
        printf(" %d files changed, %d insertions(+), %d deletions(-)\n",
               total_files, adds, dels);
 }
@@ -961,6 +953,9 @@ static void show_numstat(struct diffstat_t* data, struct diff_options *options)
 {
        int i;
 
+       if (data->nr == 0)
+               return;
+
        for (i = 0; i < data->nr; i++) {
                struct diffstat_file *file = data->files[i];
 
@@ -968,19 +963,45 @@ static void show_numstat(struct diffstat_t* data, struct diff_options *options)
                        printf("-\t-\t");
                else
                        printf("%d\t%d\t", file->added, file->deleted);
-               if (!file->is_renamed) {
-                       write_name_quoted(file->name, stdout, options->line_termination);
+               if (options->line_termination) {
+                       fill_print_name(file);
+                       if (!file->is_renamed)
+                               write_name_quoted(file->name, stdout,
+                                                 options->line_termination);
+                       else {
+                               fputs(file->print_name, stdout);
+                               putchar(options->line_termination);
+                       }
                } else {
-                       fputs(file->name, stdout);
-                       putchar(options->line_termination);
+                       if (file->is_renamed) {
+                               putchar('\0');
+                               write_name_quoted(file->from_name, stdout, '\0');
+                       }
+                       write_name_quoted(file->name, stdout, '\0');
                }
        }
 }
 
+static void free_diffstat_info(struct diffstat_t *diffstat)
+{
+       int i;
+       for (i = 0; i < diffstat->nr; i++) {
+               struct diffstat_file *f = diffstat->files[i];
+               if (f->name != f->print_name)
+                       free(f->print_name);
+               free(f->name);
+               free(f->from_name);
+               free(f);
+       }
+       free(diffstat->files);
+}
+
 struct checkdiff_t {
        struct xdiff_emit_state xm;
        const char *filename;
        int lineno, color_diff;
+       unsigned ws_rule;
+       unsigned status;
 };
 
 static void checkdiff_consume(void *priv, char *line, unsigned long len)
@@ -989,43 +1010,26 @@ static void checkdiff_consume(void *priv, char *line, unsigned long len)
        const char *ws = diff_get_color(data->color_diff, DIFF_WHITESPACE);
        const char *reset = diff_get_color(data->color_diff, DIFF_RESET);
        const char *set = diff_get_color(data->color_diff, DIFF_FILE_NEW);
+       char *err;
 
        if (line[0] == '+') {
-               int i, spaces = 0, space_before_tab = 0, white_space_at_end = 0;
-
-               /* check space before tab */
-               for (i = 1; i < len && (line[i] == ' ' || line[i] == '\t'); i++)
-                       if (line[i] == ' ')
-                               spaces++;
-               if (line[i - 1] == '\t' && spaces)
-                       space_before_tab = 1;
-
-               /* check white space at line end */
-               if (line[len - 1] == '\n')
-                       len--;
-               if (isspace(line[len - 1]))
-                       white_space_at_end = 1;
-
-               if (space_before_tab || white_space_at_end) {
-                       printf("%s:%d: %s", data->filename, data->lineno, ws);
-                       if (space_before_tab) {
-                               printf("space before tab");
-                               if (white_space_at_end)
-                                       putchar(',');
-                       }
-                       if (white_space_at_end)
-                               printf("white space at end");
-                       printf(":%s ", reset);
-                       emit_line_with_ws(1, set, reset, ws, line, len);
-               }
-
                data->lineno++;
+               data->status = check_and_emit_line(line + 1, len - 1,
+                   data->ws_rule, NULL, NULL, NULL, NULL);
+               if (!data->status)
+                       return;
+               err = whitespace_error_string(data->status);
+               printf("%s:%d: %s.\n", data->filename, data->lineno, err);
+               free(err);
+               emit_line(set, reset, line, 1);
+               (void)check_and_emit_line(line + 1, len - 1, data->ws_rule,
+                   stdout, set, reset, ws);
        } else if (line[0] == ' ')
                data->lineno++;
        else if (line[0] == '@') {
                char *plus = strchr(line, '+');
                if (plus)
-                       data->lineno = strtol(plus, NULL, 10);
+                       data->lineno = strtol(plus, NULL, 10) - 1;
                else
                        die("invalid diff");
        }
@@ -1181,7 +1185,6 @@ static const char *funcname_pattern(const char *ident)
 {
        struct funcname_pattern *pp;
 
-       read_config_if_needed();
        for (pp = funcname_pattern_list; pp; pp = pp->next)
                if (!strcmp(ident, pp->name))
                        return pp->pattern;
@@ -1223,7 +1226,7 @@ static const char *diff_funcname_pattern(struct diff_filespec *one)
 
        /*
         * And define built-in fallback patterns here.  Note that
-        * these can be overriden by the user's config settings.
+        * these can be overridden by the user's config settings.
         */
        for (i = 0; i < ARRAY_SIZE(builtin_funcname_pattern); i++)
                if (!strcmp(ident, builtin_funcname_pattern[i].name))
@@ -1243,11 +1246,11 @@ static void builtin_diff(const char *name_a,
        mmfile_t mf1, mf2;
        const char *lbl[2];
        char *a_one, *b_two;
-       const char *set = diff_get_color(o->color_diff, DIFF_METAINFO);
-       const char *reset = diff_get_color(o->color_diff, DIFF_RESET);
+       const char *set = diff_get_color_opt(o, DIFF_METAINFO);
+       const char *reset = diff_get_color_opt(o, DIFF_RESET);
 
-       a_one = quote_two("a/", name_a + (*name_a == '/'));
-       b_two = quote_two("b/", name_b + (*name_b == '/'));
+       a_one = quote_two(o->a_prefix, name_a + (*name_a == '/'));
+       b_two = quote_two(o->b_prefix, name_b + (*name_b == '/'));
        lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
        lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
        printf("%sdiff --git %s %s%s\n", set, a_one, b_two, reset);
@@ -1276,8 +1279,7 @@ static void builtin_diff(const char *name_a,
                if ((one->mode ^ two->mode) & S_IFMT)
                        goto free_ab_and_return;
                if (complete_rewrite) {
-                       emit_rewrite_diff(name_a, name_b, one, two,
-                                       o->color_diff);
+                       emit_rewrite_diff(name_a, name_b, one, two, o);
                        o->found_changes = 1;
                        goto free_ab_and_return;
                }
@@ -1286,13 +1288,13 @@ static void builtin_diff(const char *name_a,
        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
                die("unable to read files to diff");
 
-       if (!o->text &&
+       if (!DIFF_OPT_TST(o, TEXT) &&
            (diff_filespec_is_binary(one) || diff_filespec_is_binary(two))) {
                /* Quite common confusing case */
                if (mf1.size == mf2.size &&
                    !memcmp(mf1.ptr, mf2.ptr, mf1.size))
                        goto free_ab_and_return;
-               if (o->binary)
+               if (DIFF_OPT_TST(o, BINARY))
                        emit_binary_diff(&mf1, &mf2);
                else
                        printf("Binary files %s and %s differ\n",
@@ -1315,8 +1317,9 @@ static void builtin_diff(const char *name_a,
                memset(&xecfg, 0, sizeof(xecfg));
                memset(&ecbdata, 0, sizeof(ecbdata));
                ecbdata.label_path = lbl;
-               ecbdata.color_diff = o->color_diff;
+               ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
                ecbdata.found_changesp = &o->found_changes;
+               ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
                xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
                xecfg.ctxlen = o->context;
                xecfg.flags = XDL_EMIT_FUNCNAMES;
@@ -1331,11 +1334,11 @@ static void builtin_diff(const char *name_a,
                ecb.outf = xdiff_outf;
                ecb.priv = &ecbdata;
                ecbdata.xm.consume = fn_out_consume;
-               if (o->color_diff_words)
+               if (DIFF_OPT_TST(o, COLOR_DIFF_WORDS))
                        ecbdata.diff_words =
                                xcalloc(1, sizeof(struct diff_words_data));
-               xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
-               if (o->color_diff_words)
+               xdi_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
+               if (DIFF_OPT_TST(o, COLOR_DIFF_WORDS))
                        free_diff_words_data(&ecbdata);
        }
 
@@ -1387,7 +1390,7 @@ static void builtin_diffstat(const char *name_a, const char *name_b,
                xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
                ecb.outf = xdiff_outf;
                ecb.priv = diffstat;
-               xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
+               xdi_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
        }
 
  free_and_return:
@@ -1409,7 +1412,8 @@ static void builtin_checkdiff(const char *name_a, const char *name_b,
        data.xm.consume = checkdiff_consume;
        data.filename = name_b ? name_b : name_a;
        data.lineno = 0;
-       data.color_diff = o->color_diff;
+       data.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
+       data.ws_rule = whitespace_rule(data.filename);
 
        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
                die("unable to read files to diff");
@@ -1426,11 +1430,13 @@ static void builtin_checkdiff(const char *name_a, const char *name_b,
                xpp.flags = XDF_NEED_MINIMAL;
                ecb.outf = xdiff_outf;
                ecb.priv = &data;
-               xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
+               xdi_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
        }
  free_and_return:
        diff_free_filespec_data(one);
        diff_free_filespec_data(two);
+       if (data.status)
+               DIFF_OPT_SET(o, CHECK_FAILED);
 }
 
 struct diff_filespec *alloc_filespec(const char *path)
@@ -1835,7 +1841,6 @@ static const char *external_diff_attr(const char *name)
                    !ATTR_UNSET(value)) {
                        struct ll_diff_driver *drv;
 
-                       read_config_if_needed();
                        for (drv = user_diff; drv; drv = drv->next)
                                if (!strcmp(drv->name, value))
                                        return drv->cmd;
@@ -1853,7 +1858,7 @@ static void run_diff_cmd(const char *pgm,
                         struct diff_options *o,
                         int complete_rewrite)
 {
-       if (!o->allow_external)
+       if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
                pgm = NULL;
        else {
                const char *cmd = external_diff_attr(name);
@@ -1951,9 +1956,9 @@ static void run_diff(struct diff_filepair *p, struct diff_options *o)
        }
 
        if (hashcmp(one->sha1, two->sha1)) {
-               int abbrev = o->full_index ? 40 : DEFAULT_ABBREV;
+               int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
 
-               if (o->binary) {
+               if (DIFF_OPT_TST(o, BINARY)) {
                        mmfile_t mf;
                        if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
                            (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
@@ -2045,8 +2050,14 @@ void diff_setup(struct diff_options *options)
 
        options->change = diff_change;
        options->add_remove = diff_addremove;
-       options->color_diff = diff_use_color_default;
+       if (diff_use_color_default)
+               DIFF_OPT_SET(options, COLOR_DIFF);
+       else
+               DIFF_OPT_CLR(options, COLOR_DIFF);
        options->detect_rename = diff_detect_rename_default;
+
+       options->a_prefix = "a/";
+       options->b_prefix = "b/";
 }
 
 int diff_setup_done(struct diff_options *options)
@@ -2064,7 +2075,7 @@ int diff_setup_done(struct diff_options *options)
        if (count > 1)
                die("--name-only, --name-status, --check and -s are mutually exclusive");
 
-       if (options->find_copies_harder)
+       if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
                options->detect_rename = DIFF_DETECT_COPY;
 
        if (options->output_format & (DIFF_FORMAT_NAME |
@@ -2088,12 +2099,12 @@ int diff_setup_done(struct diff_options *options)
                                      DIFF_FORMAT_SHORTSTAT |
                                      DIFF_FORMAT_SUMMARY |
                                      DIFF_FORMAT_CHECKDIFF))
-               options->recursive = 1;
+               DIFF_OPT_SET(options, RECURSIVE);
        /*
         * Also pickaxe would not work very well if you do not say recursive
         */
        if (options->pickaxe)
-               options->recursive = 1;
+               DIFF_OPT_SET(options, RECURSIVE);
 
        if (options->detect_rename && options->rename_limit < 0)
                options->rename_limit = diff_rename_limit_default;
@@ -2115,9 +2126,9 @@ int diff_setup_done(struct diff_options *options)
         * to have found.  It does not make sense not to return with
         * exit code in such a case either.
         */
-       if (options->quiet) {
+       if (DIFF_OPT_TST(options, QUIET)) {
                options->output_format = DIFF_FORMAT_NO_OUTPUT;
-               options->exit_with_status = 1;
+               DIFF_OPT_SET(options, EXIT_WITH_STATUS);
        }
 
        /*
@@ -2125,7 +2136,7 @@ int diff_setup_done(struct diff_options *options)
         * upon the first hit.  We need to run diff as usual.
         */
        if (options->pickaxe || options->filter)
-               options->quiet = 0;
+               DIFF_OPT_CLR(options, QUIET);
 
        return 0;
 }
@@ -2182,21 +2193,32 @@ static int diff_scoreopt_parse(const char *opt);
 int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 {
        const char *arg = av[0];
+
+       /* Output format options */
        if (!strcmp(arg, "-p") || !strcmp(arg, "-u"))
                options->output_format |= DIFF_FORMAT_PATCH;
        else if (opt_arg(arg, 'U', "unified", &options->context))
                options->output_format |= DIFF_FORMAT_PATCH;
        else if (!strcmp(arg, "--raw"))
                options->output_format |= DIFF_FORMAT_RAW;
-       else if (!strcmp(arg, "--patch-with-raw")) {
+       else if (!strcmp(arg, "--patch-with-raw"))
                options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
-       }
-       else if (!strcmp(arg, "--numstat")) {
+       else if (!strcmp(arg, "--numstat"))
                options->output_format |= DIFF_FORMAT_NUMSTAT;
-       }
-       else if (!strcmp(arg, "--shortstat")) {
+       else if (!strcmp(arg, "--shortstat"))
                options->output_format |= DIFF_FORMAT_SHORTSTAT;
-       }
+       else if (!strcmp(arg, "--check"))
+               options->output_format |= DIFF_FORMAT_CHECKDIFF;
+       else if (!strcmp(arg, "--summary"))
+               options->output_format |= DIFF_FORMAT_SUMMARY;
+       else if (!strcmp(arg, "--patch-with-stat"))
+               options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
+       else if (!strcmp(arg, "--name-only"))
+               options->output_format |= DIFF_FORMAT_NAME;
+       else if (!strcmp(arg, "--name-status"))
+               options->output_format |= DIFF_FORMAT_NAME_STATUS;
+       else if (!strcmp(arg, "-s"))
+               options->output_format |= DIFF_FORMAT_NO_OUTPUT;
        else if (!prefixcmp(arg, "--stat")) {
                char *end;
                int width = options->stat_width;
@@ -2224,99 +2246,95 @@ int diff_opt_parse(struct diff_options *options, const char **av, int ac)
                options->stat_name_width = name_width;
                options->stat_width = width;
        }
-       else if (!strcmp(arg, "--check"))
-               options->output_format |= DIFF_FORMAT_CHECKDIFF;
-       else if (!strcmp(arg, "--summary"))
-               options->output_format |= DIFF_FORMAT_SUMMARY;
-       else if (!strcmp(arg, "--patch-with-stat")) {
-               options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
-       }
-       else if (!strcmp(arg, "-z"))
-               options->line_termination = 0;
-       else if (!prefixcmp(arg, "-l"))
-               options->rename_limit = strtoul(arg+2, NULL, 10);
-       else if (!strcmp(arg, "--full-index"))
-               options->full_index = 1;
-       else if (!strcmp(arg, "--binary")) {
-               options->output_format |= DIFF_FORMAT_PATCH;
-               options->binary = 1;
-       }
-       else if (!strcmp(arg, "-a") || !strcmp(arg, "--text")) {
-               options->text = 1;
-       }
-       else if (!strcmp(arg, "--name-only"))
-               options->output_format |= DIFF_FORMAT_NAME;
-       else if (!strcmp(arg, "--name-status"))
-               options->output_format |= DIFF_FORMAT_NAME_STATUS;
-       else if (!strcmp(arg, "-R"))
-               options->reverse_diff = 1;
-       else if (!prefixcmp(arg, "-S"))
-               options->pickaxe = arg + 2;
-       else if (!strcmp(arg, "-s")) {
-               options->output_format |= DIFF_FORMAT_NO_OUTPUT;
-       }
-       else if (!prefixcmp(arg, "-O"))
-               options->orderfile = arg + 2;
-       else if (!prefixcmp(arg, "--diff-filter="))
-               options->filter = arg + 14;
-       else if (!strcmp(arg, "--pickaxe-all"))
-               options->pickaxe_opts = DIFF_PICKAXE_ALL;
-       else if (!strcmp(arg, "--pickaxe-regex"))
-               options->pickaxe_opts = DIFF_PICKAXE_REGEX;
+
+       /* renames options */
        else if (!prefixcmp(arg, "-B")) {
-               if ((options->break_opt =
-                    diff_scoreopt_parse(arg)) == -1)
+               if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
                        return -1;
        }
        else if (!prefixcmp(arg, "-M")) {
-               if ((options->rename_score =
-                    diff_scoreopt_parse(arg)) == -1)
+               if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
                        return -1;
                options->detect_rename = DIFF_DETECT_RENAME;
        }
        else if (!prefixcmp(arg, "-C")) {
                if (options->detect_rename == DIFF_DETECT_COPY)
-                       options->find_copies_harder = 1;
-               if ((options->rename_score =
-                    diff_scoreopt_parse(arg)) == -1)
+                       DIFF_OPT_SET(options, FIND_COPIES_HARDER);
+               if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
                        return -1;
                options->detect_rename = DIFF_DETECT_COPY;
        }
-       else if (!strcmp(arg, "--find-copies-harder"))
-               options->find_copies_harder = 1;
-       else if (!strcmp(arg, "--follow"))
-               options->follow_renames = 1;
-       else if (!strcmp(arg, "--abbrev"))
-               options->abbrev = DEFAULT_ABBREV;
-       else if (!prefixcmp(arg, "--abbrev=")) {
-               options->abbrev = strtoul(arg + 9, NULL, 10);
-               if (options->abbrev < MINIMUM_ABBREV)
-                       options->abbrev = MINIMUM_ABBREV;
-               else if (40 < options->abbrev)
-                       options->abbrev = 40;
-       }
-       else if (!strcmp(arg, "--color"))
-               options->color_diff = 1;
-       else if (!strcmp(arg, "--no-color"))
-               options->color_diff = 0;
+       else if (!strcmp(arg, "--no-renames"))
+               options->detect_rename = 0;
+
+       /* xdiff options */
        else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
                options->xdl_opts |= XDF_IGNORE_WHITESPACE;
        else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
                options->xdl_opts |= XDF_IGNORE_WHITESPACE_CHANGE;
        else if (!strcmp(arg, "--ignore-space-at-eol"))
                options->xdl_opts |= XDF_IGNORE_WHITESPACE_AT_EOL;
+
+       /* flags options */
+       else if (!strcmp(arg, "--binary")) {
+               options->output_format |= DIFF_FORMAT_PATCH;
+               DIFF_OPT_SET(options, BINARY);
+       }
+       else if (!strcmp(arg, "--full-index"))
+               DIFF_OPT_SET(options, FULL_INDEX);
+       else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
+               DIFF_OPT_SET(options, TEXT);
+       else if (!strcmp(arg, "-R"))
+               DIFF_OPT_SET(options, REVERSE_DIFF);
+       else if (!strcmp(arg, "--find-copies-harder"))
+               DIFF_OPT_SET(options, FIND_COPIES_HARDER);
+       else if (!strcmp(arg, "--follow"))
+               DIFF_OPT_SET(options, FOLLOW_RENAMES);
+       else if (!strcmp(arg, "--color"))
+               DIFF_OPT_SET(options, COLOR_DIFF);
+       else if (!strcmp(arg, "--no-color"))
+               DIFF_OPT_CLR(options, COLOR_DIFF);
        else if (!strcmp(arg, "--color-words"))
-               options->color_diff = options->color_diff_words = 1;
-       else if (!strcmp(arg, "--no-renames"))
-               options->detect_rename = 0;
+               options->flags |= DIFF_OPT_COLOR_DIFF | DIFF_OPT_COLOR_DIFF_WORDS;
        else if (!strcmp(arg, "--exit-code"))
-               options->exit_with_status = 1;
+               DIFF_OPT_SET(options, EXIT_WITH_STATUS);
        else if (!strcmp(arg, "--quiet"))
-               options->quiet = 1;
+               DIFF_OPT_SET(options, QUIET);
        else if (!strcmp(arg, "--ext-diff"))
-               options->allow_external = 1;
+               DIFF_OPT_SET(options, ALLOW_EXTERNAL);
        else if (!strcmp(arg, "--no-ext-diff"))
-               options->allow_external = 0;
+               DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
+
+       /* misc options */
+       else if (!strcmp(arg, "-z"))
+               options->line_termination = 0;
+       else if (!prefixcmp(arg, "-l"))
+               options->rename_limit = strtoul(arg+2, NULL, 10);
+       else if (!prefixcmp(arg, "-S"))
+               options->pickaxe = arg + 2;
+       else if (!strcmp(arg, "--pickaxe-all"))
+               options->pickaxe_opts = DIFF_PICKAXE_ALL;
+       else if (!strcmp(arg, "--pickaxe-regex"))
+               options->pickaxe_opts = DIFF_PICKAXE_REGEX;
+       else if (!prefixcmp(arg, "-O"))
+               options->orderfile = arg + 2;
+       else if (!prefixcmp(arg, "--diff-filter="))
+               options->filter = arg + 14;
+       else if (!strcmp(arg, "--abbrev"))
+               options->abbrev = DEFAULT_ABBREV;
+       else if (!prefixcmp(arg, "--abbrev=")) {
+               options->abbrev = strtoul(arg + 9, NULL, 10);
+               if (options->abbrev < MINIMUM_ABBREV)
+                       options->abbrev = MINIMUM_ABBREV;
+               else if (40 < options->abbrev)
+                       options->abbrev = 40;
+       }
+       else if (!prefixcmp(arg, "--src-prefix="))
+               options->a_prefix = arg + 13;
+       else if (!prefixcmp(arg, "--dst-prefix="))
+               options->b_prefix = arg + 13;
+       else if (!strcmp(arg, "--no-prefix"))
+               options->a_prefix = options->b_prefix = "";
        else
                return 0;
        return 1;
@@ -2712,7 +2730,7 @@ static void diff_summary(struct diff_filepair *p)
                break;
        default:
                if (p->score) {
-                       puts(" rewrite ");
+                       fputs(" rewrite ", stdout);
                        write_name_quoted(p->two->path, stdout, ' ');
                        printf("(%d%%)\n", similarity_index(p));
                }
@@ -2834,7 +2852,7 @@ static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
                xecfg.flags = XDL_EMIT_FUNCNAMES;
                ecb.outf = xdiff_outf;
                ecb.priv = &data;
-               xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
+               xdi_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
        }
 
        SHA1_Final(sha1, &ctx);
@@ -2921,8 +2939,9 @@ void diff_flush(struct diff_options *options)
                        show_numstat(&diffstat, options);
                if (output_format & DIFF_FORMAT_DIFFSTAT)
                        show_stats(&diffstat, options);
-               else if (output_format & DIFF_FORMAT_SHORTSTAT)
+               if (output_format & DIFF_FORMAT_SHORTSTAT)
                        show_shortstats(&diffstat);
+               free_diffstat_info(&diffstat);
                separator++;
        }
 
@@ -3071,7 +3090,7 @@ static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
                         * to determine how many paths were dirty only
                         * due to stat info mismatch.
                         */
-                       if (!diffopt->no_index)
+                       if (!DIFF_OPT_TST(diffopt, NO_INDEX))
                                diffopt->skip_stat_unmatch++;
                        diff_free_filepair(p);
                }
@@ -3082,10 +3101,10 @@ static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
 
 void diffcore_std(struct diff_options *options)
 {
-       if (options->quiet)
+       if (DIFF_OPT_TST(options, QUIET))
                return;
 
-       if (options->skip_stat_unmatch && !options->find_copies_harder)
+       if (options->skip_stat_unmatch && !DIFF_OPT_TST(options, FIND_COPIES_HARDER))
                diffcore_skip_stat_unmatch(options);
        if (options->break_opt != -1)
                diffcore_break(options->break_opt);
@@ -3100,9 +3119,26 @@ void diffcore_std(struct diff_options *options)
        diff_resolve_rename_copy();
        diffcore_apply_filter(options->filter);
 
-       options->has_changes = !!diff_queued_diff.nr;
+       if (diff_queued_diff.nr)
+               DIFF_OPT_SET(options, HAS_CHANGES);
+       else
+               DIFF_OPT_CLR(options, HAS_CHANGES);
 }
 
+int diff_result_code(struct diff_options *opt, int status)
+{
+       int result = 0;
+       if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
+           !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
+               return status;
+       if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
+           DIFF_OPT_TST(opt, HAS_CHANGES))
+               result |= 01;
+       if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
+           DIFF_OPT_TST(opt, CHECK_FAILED))
+               result |= 02;
+       return result;
+}
 
 void diff_addremove(struct diff_options *options,
                    int addremove, unsigned mode,
@@ -3124,7 +3160,7 @@ void diff_addremove(struct diff_options *options,
         * Before the final output happens, they are pruned after
         * merged into rename/copy pairs as appropriate.
         */
-       if (options->reverse_diff)
+       if (DIFF_OPT_TST(options, REVERSE_DIFF))
                addremove = (addremove == '+' ? '-' :
                             addremove == '-' ? '+' : addremove);
 
@@ -3139,7 +3175,7 @@ void diff_addremove(struct diff_options *options,
                fill_filespec(two, sha1, mode);
 
        diff_queue(&diff_queued_diff, one, two);
-       options->has_changes = 1;
+       DIFF_OPT_SET(options, HAS_CHANGES);
 }
 
 void diff_change(struct diff_options *options,
@@ -3151,7 +3187,7 @@ void diff_change(struct diff_options *options,
        char concatpath[PATH_MAX];
        struct diff_filespec *one, *two;
 
-       if (options->reverse_diff) {
+       if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
                unsigned tmp;
                const unsigned char *tmp_c;
                tmp = old_mode; old_mode = new_mode; new_mode = tmp;
@@ -3165,7 +3201,7 @@ void diff_change(struct diff_options *options,
        fill_filespec(two, new_sha1, new_mode);
 
        diff_queue(&diff_queued_diff, one, two);
-       options->has_changes = 1;
+       DIFF_OPT_SET(options, HAS_CHANGES);
 }
 
 void diff_unmerge(struct diff_options *options,