[PATCH] git-apply: Don't barf when --stat'ing a diff with no line changes.
[gitweb.git] / diff.c
diff --git a/diff.c b/diff.c
index a080d94c37c8a99cdbc3b8ed510c4a52cea508e8..5cb340ca093a4f2285d2c40ee8e83ed0af14cff1 100644 (file)
--- a/diff.c
+++ b/diff.c
@@ -83,10 +83,88 @@ static struct diff_tempfile {
        char tmp_path[50];
 } diff_temp[2];
 
+static int count_lines(const char *filename)
+{
+       FILE *in;
+       int count, ch, completely_empty = 1, nl_just_seen = 0;
+       in = fopen(filename, "r");
+       count = 0;
+       while ((ch = fgetc(in)) != EOF)
+               if (ch == '\n') {
+                       count++;
+                       nl_just_seen = 1;
+                       completely_empty = 0;
+               }
+               else {
+                       nl_just_seen = 0;
+                       completely_empty = 0;
+               }
+       fclose(in);
+       if (completely_empty)
+               return 0;
+       if (!nl_just_seen)
+               count++; /* no trailing newline */
+       return count;
+}
+
+static void print_line_count(int count)
+{
+       switch (count) {
+       case 0:
+               printf("0,0");
+               break;
+       case 1:
+               printf("1");
+               break;
+       default:
+               printf("1,%d", count);
+               break;
+       }
+}
+
+static void copy_file(int prefix, const char *filename)
+{
+       FILE *in;
+       int ch, nl_just_seen = 1;
+       in = fopen(filename, "r");
+       while ((ch = fgetc(in)) != EOF) {
+               if (nl_just_seen)
+                       putchar(prefix);
+               putchar(ch);
+               if (ch == '\n')
+                       nl_just_seen = 1;
+               else
+                       nl_just_seen = 0;
+       }
+       fclose(in);
+       if (!nl_just_seen)
+               printf("\n\\ No newline at end of file\n");
+}
+
+static void emit_rewrite_diff(const char *name_a,
+                             const char *name_b,
+                             struct diff_tempfile *temp)
+{
+       /* Use temp[i].name as input, name_a and name_b as labels */
+       int lc_a, lc_b;
+       lc_a = count_lines(temp[0].name);
+       lc_b = count_lines(temp[1].name);
+       printf("--- %s\n+++ %s\n@@ -", name_a, name_b);
+       print_line_count(lc_a);
+       printf(" +");
+       print_line_count(lc_b);
+       printf(" @@\n");
+       if (lc_a)
+               copy_file('-', temp[0].name);
+       if (lc_b)
+               copy_file('+', temp[1].name);
+}
+
 static void builtin_diff(const char *name_a,
                         const char *name_b,
                         struct diff_tempfile *temp,
-                        const char *xfrm_msg)
+                        const char *xfrm_msg,
+                        int complete_rewrite)
 {
        int i, next_at, cmd_size;
        const char *diff_cmd = "diff -L'%s%s' -L'%s%s'";
@@ -132,10 +210,16 @@ static void builtin_diff(const char *name_a,
                            diff_arg, input_name_sq[0], input_name_sq[1]);
 
        printf("diff --git a/%s b/%s\n", name_a, name_b);
-       if (!path1[0][0])
+       if (!path1[0][0]) {
                printf("new file mode %s\n", temp[1].mode);
-       else if (!path1[1][0])
+               if (xfrm_msg && xfrm_msg[0])
+                       puts(xfrm_msg);
+       }
+       else if (!path1[1][0]) {
                printf("deleted file mode %s\n", temp[0].mode);
+               if (xfrm_msg && xfrm_msg[0])
+                       puts(xfrm_msg);
+       }
        else {
                if (strcmp(temp[0].mode, temp[1].mode)) {
                        printf("old mode %s\n", temp[0].mode);
@@ -143,12 +227,16 @@ static void builtin_diff(const char *name_a,
                }
                if (xfrm_msg && xfrm_msg[0])
                        puts(xfrm_msg);
-
                if (strncmp(temp[0].mode, temp[1].mode, 3))
                        /* we do not run diff between different kind
                         * of objects.
                         */
                        exit(0);
+               if (complete_rewrite) {
+                       fflush(NULL);
+                       emit_rewrite_diff(name_a, name_b, temp);
+                       exit(0);
+               }
        }
        fflush(NULL);
        execlp("/bin/sh","sh", "-c", cmd, NULL);
@@ -230,6 +318,7 @@ static struct sha1_size_cache {
 static int sha1_size_cache_nr, sha1_size_cache_alloc;
 
 static struct sha1_size_cache *locate_size_cache(unsigned char *sha1,
+                                                int find_only,
                                                 unsigned long size)
 {
        int first, last;
@@ -238,9 +327,9 @@ static struct sha1_size_cache *locate_size_cache(unsigned char *sha1,
        first = 0;
        last = sha1_size_cache_nr;
        while (last > first) {
-               int next = (last + first) >> 1;
+               int cmp, next = (last + first) >> 1;
                e = sha1_size_cache[next];
-               int cmp = memcmp(e->sha1, sha1, 20);
+               cmp = memcmp(e->sha1, sha1, 20);
                if (!cmp)
                        return e;
                if (cmp < 0) {
@@ -250,7 +339,7 @@ static struct sha1_size_cache *locate_size_cache(unsigned char *sha1,
                first = next+1;
        }
        /* not found */
-       if (size == UINT_MAX)
+       if (find_only)
                return NULL;
        /* insert to make it at "first" */
        if (sha1_size_cache_alloc <= sha1_size_cache_nr) {
@@ -327,21 +416,22 @@ int diff_populate_filespec(struct diff_filespec *s, int size_only)
                close(fd);
        }
        else {
-               /* We cannot do size only for SHA1 blobs */
                char type[20];
                struct sha1_size_cache *e;
 
                if (size_only) {
-                       e = locate_size_cache(s->sha1, UINT_MAX);
+                       e = locate_size_cache(s->sha1, 1, 0);
                        if (e) {
                                s->size = e->size;
                                return 0;
                        }
+                       if (!sha1_file_size(s->sha1, &s->size))
+                               locate_size_cache(s->sha1, 0, s->size);
+               }
+               else {
+                       s->data = read_sha1_file(s->sha1, type, &s->size);
+                       s->should_free = 1;
                }
-               s->data = read_sha1_file(s->sha1, type, &s->size);
-               s->should_free = 1;
-               if (s->data && size_only)
-                       locate_size_cache(s->sha1, s->size);
        }
        return 0;
 }
@@ -466,7 +556,8 @@ static void run_external_diff(const char *pgm,
                              const char *other,
                              struct diff_filespec *one,
                              struct diff_filespec *two,
-                             const char *xfrm_msg)
+                             const char *xfrm_msg,
+                             int complete_rewrite)
 {
        struct diff_tempfile *temp = diff_temp;
        pid_t pid;
@@ -516,7 +607,8 @@ static void run_external_diff(const char *pgm,
                 * otherwise we use the built-in one.
                 */
                if (one && two)
-                       builtin_diff(name, other ? : name, temp, xfrm_msg);
+                       builtin_diff(name, other ? : name, temp, xfrm_msg,
+                                    complete_rewrite);
                else
                        printf("* Unmerged path %s\n", name);
                exit(0);
@@ -539,13 +631,59 @@ static void run_external_diff(const char *pgm,
        remove_tempfile();
 }
 
-static void run_diff(const char *name,
-                    const char *other,
-                    struct diff_filespec *one,
-                    struct diff_filespec *two,
-                    const char *xfrm_msg)
+static void run_diff(struct diff_filepair *p)
 {
        const char *pgm = external_diff();
+       char msg_[PATH_MAX*2+200], *xfrm_msg;
+       struct diff_filespec *one;
+       struct diff_filespec *two;
+       const char *name;
+       const char *other;
+       int complete_rewrite = 0;
+
+       if (DIFF_PAIR_UNMERGED(p)) {
+               /* unmerged */
+               run_external_diff(pgm, p->one->path, NULL, NULL, NULL, NULL,
+                                 0);
+               return;
+       }
+
+       name = p->one->path;
+       other = (strcmp(name, p->two->path) ? p->two->path : NULL);
+       one = p->one; two = p->two;
+       switch (p->status) {
+       case 'C':
+               sprintf(msg_,
+                       "similarity index %d%%\n"
+                       "copy from %s\n"
+                       "copy to %s",
+                       (int)(0.5 + p->score * 100.0/MAX_SCORE),
+                       name, other);
+               xfrm_msg = msg_;
+               break;
+       case 'R':
+               sprintf(msg_,
+                       "similarity index %d%%\n"
+                       "rename from %s\n"
+                       "rename to %s",
+                       (int)(0.5 + p->score * 100.0/MAX_SCORE),
+                       name, other);
+               xfrm_msg = msg_;
+               break;
+       case 'M':
+               if (p->score) {
+                       sprintf(msg_,
+                               "dissimilarity index %d%%",
+                               (int)(0.5 + p->score * 100.0/MAX_SCORE));
+                       xfrm_msg = msg_;
+                       complete_rewrite = 1;
+                       break;
+               }
+               /* fallthru */
+       default:
+               xfrm_msg = NULL;
+       }
+
        if (!pgm &&
            DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
            (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
@@ -553,14 +691,15 @@ static void run_diff(const char *name,
                 * needs to be split into deletion and creation.
                 */
                struct diff_filespec *null = alloc_filespec(two->path);
-               run_external_diff(NULL, name, other, one, null, xfrm_msg);
+               run_external_diff(NULL, name, other, one, null, xfrm_msg, 0);
                free(null);
                null = alloc_filespec(one->path);
-               run_external_diff(NULL, name, other, null, two, xfrm_msg);
+               run_external_diff(NULL, name, other, null, two, xfrm_msg, 0);
                free(null);
        }
        else
-               run_external_diff(pgm, name, other, one, two, xfrm_msg);
+               run_external_diff(pgm, name, other, one, two, xfrm_msg,
+                                 complete_rewrite);
 }
 
 void diff_setup(int flags)
@@ -582,6 +721,57 @@ void diff_setup(int flags)
        
 }
 
+static int parse_num(const char **cp_p)
+{
+       int num, scale, ch, cnt;
+       const char *cp = *cp_p;
+
+       cnt = num = 0;
+       scale = 1;
+       while ('0' <= (ch = *cp) && ch <= '9') {
+               if (cnt++ < 5) {
+                       /* We simply ignore more than 5 digits precision. */
+                       scale *= 10;
+                       num = num * 10 + ch - '0';
+               }
+               *cp++;
+       }
+       *cp_p = cp;
+
+       /* user says num divided by scale and we say internally that
+        * is MAX_SCORE * num / scale.
+        */
+       return (MAX_SCORE * num / scale);
+}
+
+int diff_scoreopt_parse(const char *opt)
+{
+       int opt1, opt2, cmd;
+
+       if (*opt++ != '-')
+               return -1;
+       cmd = *opt++;
+       if (cmd != 'M' && cmd != 'C' && cmd != 'B')
+               return -1; /* that is not a -M, -C nor -B option */
+
+       opt1 = parse_num(&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_num(&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)
@@ -602,7 +792,9 @@ struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
        dp->one = one;
        dp->two = two;
        dp->score = 0;
+       dp->status = 0;
        dp->source_stays = 0;
+       dp->broken_pair = 0;
        diff_q(queue, dp);
        return dp;
 }
@@ -631,16 +823,22 @@ static void diff_flush_raw(struct diff_filepair *p,
                        die(err, p->two->path);
        }
 
+       if (p->score)
+               sprintf(status, "%c%03d", p->status,
+                       (int)(0.5 + p->score * 100.0/MAX_SCORE));
+       else {
+               status[0] = p->status;
+               status[1] = 0;
+       }
        switch (p->status) {
        case 'C': case 'R':
                two_paths = 1;
-               sprintf(status, "%c%03d", p->status,
-                       (int)(0.5 + p->score * 100.0/MAX_SCORE));
+               break;
+       case 'N': case 'D':
+               two_paths = 0;
                break;
        default:
                two_paths = 0;
-               status[0] = p->status;
-               status[1] = 0;
                break;
        }
        printf(":%06o %06o %s ",
@@ -691,45 +889,14 @@ int diff_unmodified_pair(struct diff_filepair *p)
 
 static void diff_flush_patch(struct diff_filepair *p)
 {
-       const char *name, *other;
-       char msg_[PATH_MAX*2+200], *msg;
-
        if (diff_unmodified_pair(p))
                return;
 
-       name = p->one->path;
-       other = (strcmp(name, p->two->path) ? p->two->path : NULL);
        if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
            (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
                return; /* no tree diffs in patch format */ 
 
-       switch (p->status) {
-       case 'C':
-               sprintf(msg_,
-                       "similarity index %d%%\n"
-                       "copy from %s\n"
-                       "copy to %s",
-                       (int)(0.5 + p->score * 100.0/MAX_SCORE),
-                       p->one->path, p->two->path);
-               msg = msg_;
-               break;
-       case 'R':
-               sprintf(msg_,
-                       "similarity index %d%%\n"
-                       "rename old %s\n"
-                       "rename new %s",
-                       (int)(0.5 + p->score * 100.0/MAX_SCORE),
-                       p->one->path, p->two->path);
-               msg = msg_;
-               break;
-       default:
-               msg = NULL;
-       }
-
-       if (DIFF_PAIR_UNMERGED(p))
-               run_diff(name, NULL, NULL, NULL, NULL);
-       else
-               run_diff(name, other, p->one, p->two, msg);
+       run_diff(p);
 }
 
 int diff_queue_is_empty(void)
@@ -760,8 +927,9 @@ void diff_debug_filepair(const struct diff_filepair *p, int i)
 {
        diff_debug_filespec(p->one, i, "one");
        diff_debug_filespec(p->two, i, "two");
-       fprintf(stderr, "score %d, status %c source_stays %d\n",
-               p->score, p->status ? : '?', p->source_stays);
+       fprintf(stderr, "score %d, status %c stays %d broken %d\n",
+               p->score, p->status ? : '?',
+               p->source_stays, p->broken_pair);
 }
 
 void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
@@ -826,17 +994,19 @@ static void diff_resolve_rename_copy(void)
                else if (memcmp(p->one->sha1, p->two->sha1, 20) ||
                         p->one->mode != p->two->mode)
                        p->status = 'M';
-               else
-                       /* this is a "no-change" entry.
-                        * should not happen anymore.
-                        * p->status = 'X';
+               else {
+                       /* This is a "no-change" entry and should not
+                        * happen anymore, but prepare for broken callers.
                         */
-                       die("internal error in diffcore: unmodified entry remains");
+                       error("feeding unmodified %s to diffcore",
+                             p->one->path);
+                       p->status = 'X';
+               }
        }
        diff_debug_queue("resolve-rename-copy done", q);
 }
 
-void diff_flush(int diff_output_style, int resolve_rename_copy)
+void diff_flush(int diff_output_style)
 {
        struct diff_queue_struct *q = &diff_queued_diff;
        int i;
@@ -845,8 +1015,6 @@ void diff_flush(int diff_output_style, int resolve_rename_copy)
 
        if (diff_output_style == DIFF_FORMAT_MACHINE)
                line_termination = inter_name_termination = 0;
-       if (resolve_rename_copy)
-               diff_resolve_rename_copy();
 
        for (i = 0; i < q->nr; i++) {
                struct diff_filepair *p = q->queue[i];
@@ -873,16 +1041,92 @@ void diff_flush(int diff_output_style, int resolve_rename_copy)
        q->nr = q->alloc = 0;
 }
 
+static void diffcore_apply_filter(const char *filter)
+{
+       int i;
+       struct diff_queue_struct *q = &diff_queued_diff;
+       struct diff_queue_struct outq;
+       outq.queue = NULL;
+       outq.nr = outq.alloc = 0;
+
+       if (!filter)
+               return;
+
+       if (strchr(filter, 'A')) {
+               /* All-or-none */
+               int found;
+               for (i = found = 0; !found && i < q->nr; i++) {
+                       struct diff_filepair *p = q->queue[i];
+                       if (((p->status == 'M') &&
+                            ((p->score && strchr(filter, 'B')) ||
+                             (!p->score && strchr(filter, 'M')))) ||
+                           ((p->status != 'M') && strchr(filter, p->status)))
+                               found++;
+               }
+               if (found)
+                       return;
+
+               /* otherwise we will clear the whole queue
+                * by copying the empty outq at the end of this
+                * function, but first clear the current entries
+                * in the queue.
+                */
+               for (i = 0; i < q->nr; i++)
+                       diff_free_filepair(q->queue[i]);
+       }
+       else {
+               /* Only the matching ones */
+               for (i = 0; i < q->nr; i++) {
+                       struct diff_filepair *p = q->queue[i];
+                       if (((p->status == 'M') &&
+                            ((p->score && strchr(filter, 'B')) ||
+                             (!p->score && strchr(filter, 'M')))) ||
+                           ((p->status != 'M') && strchr(filter, p->status)))
+                               diff_q(&outq, p);
+                       else
+                               diff_free_filepair(p);
+               }
+       }
+       free(q->queue);
+       *q = outq;
+}
+
 void diffcore_std(const char **paths,
                  int detect_rename, int rename_score,
-                 const char *pickaxe, int pickaxe_opts)
+                 const char *pickaxe, int pickaxe_opts,
+                 int break_opt,
+                 const char *orderfile,
+                 const char *filter)
 {
        if (paths && paths[0])
                diffcore_pathspec(paths);
+       if (break_opt != -1)
+               diffcore_break(break_opt);
        if (detect_rename)
                diffcore_rename(detect_rename, rename_score);
+       if (break_opt != -1)
+               diffcore_merge_broken();
+       if (pickaxe)
+               diffcore_pickaxe(pickaxe, pickaxe_opts);
+       if (orderfile)
+               diffcore_order(orderfile);
+       diff_resolve_rename_copy();
+       diffcore_apply_filter(filter);
+}
+
+
+void diffcore_std_no_resolve(const char **paths,
+                            const char *pickaxe, int pickaxe_opts,
+                            const char *orderfile,
+                            const char *filter)
+{
+       if (paths && paths[0])
+               diffcore_pathspec(paths);
        if (pickaxe)
                diffcore_pickaxe(pickaxe, pickaxe_opts);
+       if (orderfile)
+               diffcore_order(orderfile);
+       diffcore_apply_filter(filter);
 }
 
 void diff_addremove(int addremove, unsigned mode,