diff --stat: do not drop rename information.

When a verbatim rename or copy is detected, we did not show
anything on the "diff --stat" for the filepair.  This makes it
to show the rename information.

Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/diff-lib.c b/diff-lib.c
index 0a832c3..13b216f 100644 (file)
--- a/diff-lib.c
+++ b/diff-lib.c
@@ -195,6 +195,56 @@ static int fn_out(void *priv, mmbuffer_t *mb, int nbuf)
        return 0;
 }
 
+static char *pprint_rename(const char *a, const char *b)
+{
+       const char *old = a;
+       const char *new = b;
+       char *name = NULL;
+       int pfx_length, sfx_length;
+       int len_a = strlen(a);
+       int len_b = strlen(b);
+
+       /* Find common prefix */
+       pfx_length = 0;
+       while (*old && *new && *old == *new) {
+               if (*old == '/')
+                       pfx_length = old - a + 1;
+               old++;
+               new++;
+       }
+
+       /* Find common suffix */
+       old = a + len_a;
+       new = b + len_b;
+       sfx_length = 0;
+       while (a <= old && b <= new && *old == *new) {
+               if (*old == '/')
+                       sfx_length = len_a - (old - a);
+               old--;
+               new--;
+       }
+
+       /*
+        * pfx{mid-a => mid-b}sfx
+        * {pfx-a => pfx-b}sfx
+        * pfx{sfx-a => sfx-b}
+        * name-a => name-b
+        */
+       if (pfx_length + sfx_length) {
+               name = xmalloc(len_a + len_b - pfx_length - sfx_length + 7);
+               sprintf(name, "%.*s{%.*s => %.*s}%s",
+                       pfx_length, a,
+                       len_a - pfx_length - sfx_length, a + pfx_length,
+                       len_b - pfx_length - sfx_length, b + pfx_length,
+                       a + len_a - sfx_length);
+       }
+       else {
+               name = xmalloc(len_a + len_b + 5);
+               sprintf(name, "%s => %s", a, b);
+       }
+       return name;
+}
+
 struct diffstat_t {
        struct xdiff_emit_state xm;
 
@@ -204,12 +254,14 @@ struct diffstat_t {
                char *name;
                unsigned is_unmerged:1;
                unsigned is_binary:1;
+               unsigned is_renamed:1;
                unsigned int added, deleted;
        } **files;
 };
 
 static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
-               const char *name)
+                                         const char *name_a,
+                                         const char *name_b)
 {
        struct diffstat_file *x;
        x = xcalloc(sizeof (*x), 1);
@@ -219,7 +271,12 @@ static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
                                diffstat->alloc * sizeof(x));
        }
        diffstat->files[diffstat->nr++] = x;
-       x->name = strdup(name);
+       if (name_b) {
+               x->name = pprint_rename(name_a, name_b);
+               x->is_renamed = 1;
+       }
+       else
+               x->name = strdup(name_a);
        return x;
 }
 
@@ -305,7 +362,8 @@ static void show_stats(struct diffstat_t* data)
                        printf(" %s%-*s |  Unmerged\n", prefix, len, name);
                        goto free_diffstat_file;
                }
-               else if (added + deleted == 0) {
+               else if (!data->files[i]->is_renamed &&
+                        (added + deleted == 0)) {
                        total_files--;
                        goto free_diffstat_file;
                }
@@ -425,13 +483,14 @@ static void builtin_diff(const char *name_a,
 }
 
 static void builtin_diffstat(const char *name_a, const char *name_b,
-               struct diff_filespec *one, struct diff_filespec *two,
-               struct diffstat_t *diffstat)
+                            struct diff_filespec *one,
+                            struct diff_filespec *two,
+                            struct diffstat_t *diffstat)
 {
        mmfile_t mf1, mf2;
        struct diffstat_file *data;
 
-       data = diffstat_add(diffstat, name_a ? name_a : name_b);
+       data = diffstat_add(diffstat, name_a, name_b);
 
        if (!one || !two) {
                data->is_unmerged = 1;
@@ -992,7 +1051,7 @@ static void run_diff(struct diff_filepair *p, struct diff_options *o)
 }
 
 static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
-               struct diffstat_t *diffstat)
+                        struct diffstat_t *diffstat)
 {
        const char *name;
        const char *other;
@@ -1374,7 +1433,7 @@ static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
 }
 
 static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
-               struct diffstat_t *diffstat)
+                           struct diffstat_t *diffstat)
 {
        if (diff_unmodified_pair(p))
                return;
@@ -1559,7 +1618,7 @@ void diff_flush(struct diff_options *options)
                for (i = 0; i < q->nr; i++) {
                        struct diff_filepair *p = q->queue[i];
                        flush_one_pair(p, DIFF_FORMAT_DIFFSTAT, options,
-                                       diffstat);
+                                      diffstat);
                }
                show_stats(diffstat);
                free(diffstat);