auto-detect changed prefix and/or changed build flags
[gitweb.git] / diff.c
diff --git a/diff.c b/diff.c
index f1b672d2dc29d22a38aa057a1a927b8ad60d5e15..9e9cfc8b75b7b761980b0d32cb0c516ea3505ba3 100644 (file)
--- a/diff.c
+++ b/diff.c
@@ -8,6 +8,7 @@
 #include "quote.h"
 #include "diff.h"
 #include "diffcore.h"
+#include "delta.h"
 #include "xdiff-interface.h"
 
 static int use_size_cache;
@@ -195,6 +196,61 @@ 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) {
+               int a_midlen = len_a - pfx_length - sfx_length;
+               int b_midlen = len_b - pfx_length - sfx_length;
+               if (a_midlen < 0) a_midlen = 0;
+               if (b_midlen < 0) b_midlen = 0;
+
+               name = xmalloc(pfx_length + a_midlen + b_midlen + sfx_length + 7);
+               sprintf(name, "%.*s{%.*s => %.*s}%s",
+                       pfx_length, a,
+                       a_midlen, a + pfx_length,
+                       b_midlen, 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;
 
@@ -202,12 +258,16 @@ struct diffstat_t {
        int alloc;
        struct diffstat_file {
                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);
@@ -217,7 +277,12 @@ 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;
 }
 
@@ -234,10 +299,10 @@ static void diffstat_consume(void *priv, char *line, unsigned long len)
 
 static const char pluses[] = "++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++";
 static const char minuses[]= "----------------------------------------------------------------------";
+const char mime_boundary_leader[] = "------------";
 
 static void show_stats(struct diffstat_t* data)
 {
-       char *prefix = "";
        int i, len, add, del, total, adds = 0, dels = 0;
        int max, max_change = 0, max_len = 0;
        int total_files = data->nr;
@@ -245,19 +310,21 @@ static void show_stats(struct diffstat_t* data)
        if (data->nr == 0)
                return;
 
-       printf("---\n");
-
        for (i = 0; i < data->nr; i++) {
                struct diffstat_file *file = data->files[i];
 
-               if (max_change < file->added + file->deleted)
-                       max_change = file->added + file->deleted;
                len = strlen(file->name);
                if (max_len < len)
                        max_len = len;
+
+               if (file->is_binary || file->is_unmerged)
+                       continue;
+               if (max_change < file->added + file->deleted)
+                       max_change = file->added + file->deleted;
        }
 
        for (i = 0; i < data->nr; i++) {
+               char *prefix = "";
                char *name = data->files[i]->name;
                int added = data->files[i]->added;
                int deleted = data->files[i]->deleted;
@@ -294,11 +361,16 @@ static void show_stats(struct diffstat_t* data)
                if (max + len > 70)
                        max = 70 - len;
 
-               if (added < 0) {
-                       /* binary file */
+               if (data->files[i]->is_binary) {
                        printf(" %s%-*s |  Bin\n", prefix, len, name);
                        goto free_diffstat_file;
-               } else if (added + deleted == 0) {
+               }
+               else if (data->files[i]->is_unmerged) {
+                       printf(" %s%-*s |  Unmerged\n", prefix, len, name);
+                       goto free_diffstat_file;
+               }
+               else if (!data->files[i]->is_renamed &&
+                        (added + deleted == 0)) {
                        total_files--;
                        goto free_diffstat_file;
                }
@@ -326,6 +398,130 @@ static void show_stats(struct diffstat_t* data)
                        total_files, adds, dels);
 }
 
+struct checkdiff_t {
+       struct xdiff_emit_state xm;
+       const char *filename;
+       int lineno;
+};
+
+static void checkdiff_consume(void *priv, char *line, unsigned long len)
+{
+       struct checkdiff_t *data = priv;
+
+       if (line[0] == '+') {
+               int i, spaces = 0;
+
+               data->lineno++;
+
+               /* 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)
+                       printf("%s:%d: space before tab:%.*s\n",
+                               data->filename, data->lineno, (int)len, line);
+
+               /* check white space at line end */
+               if (line[len - 1] == '\n')
+                       len--;
+               if (isspace(line[len - 1]))
+                       printf("%s:%d: white space at end: %.*s\n",
+                               data->filename, data->lineno, (int)len, line);
+       } else if (line[0] == ' ')
+               data->lineno++;
+       else if (line[0] == '@') {
+               char *plus = strchr(line, '+');
+               if (plus)
+                       data->lineno = strtol(plus, NULL, 10);
+               else
+                       die("invalid diff");
+       }
+}
+
+static unsigned char *deflate_it(char *data,
+                                unsigned long size,
+                                unsigned long *result_size)
+{
+       int bound;
+       unsigned char *deflated;
+       z_stream stream;
+
+       memset(&stream, 0, sizeof(stream));
+       deflateInit(&stream, Z_BEST_COMPRESSION);
+       bound = deflateBound(&stream, size);
+       deflated = xmalloc(bound);
+       stream.next_out = deflated;
+       stream.avail_out = bound;
+
+       stream.next_in = (unsigned char *)data;
+       stream.avail_in = size;
+       while (deflate(&stream, Z_FINISH) == Z_OK)
+               ; /* nothing */
+       deflateEnd(&stream);
+       *result_size = stream.total_out;
+       return deflated;
+}
+
+static void emit_binary_diff(mmfile_t *one, mmfile_t *two)
+{
+       void *cp;
+       void *delta;
+       void *deflated;
+       void *data;
+       unsigned long orig_size;
+       unsigned long delta_size;
+       unsigned long deflate_size;
+       unsigned long data_size;
+
+       printf("GIT binary patch\n");
+       /* We could do deflated delta, or we could do just deflated two,
+        * whichever is smaller.
+        */
+       delta = NULL;
+       deflated = deflate_it(two->ptr, two->size, &deflate_size);
+       if (one->size && two->size) {
+               delta = diff_delta(one->ptr, one->size,
+                                  two->ptr, two->size,
+                                  &delta_size, deflate_size);
+               if (delta) {
+                       void *to_free = delta;
+                       orig_size = delta_size;
+                       delta = deflate_it(delta, delta_size, &delta_size);
+                       free(to_free);
+               }
+       }
+
+       if (delta && delta_size < deflate_size) {
+               printf("delta %lu\n", orig_size);
+               free(deflated);
+               data = delta;
+               data_size = delta_size;
+       }
+       else {
+               printf("literal %lu\n", two->size);
+               free(delta);
+               data = deflated;
+               data_size = deflate_size;
+       }
+
+       /* emit data encoded in base85 */
+       cp = data;
+       while (data_size) {
+               int bytes = (52 < data_size) ? 52 : data_size;
+               char line[70];
+               data_size -= bytes;
+               if (bytes <= 26)
+                       line[0] = bytes + 'A' - 1;
+               else
+                       line[0] = bytes - 26 + 'a' - 1;
+               encode_85(line + 1, cp, bytes);
+               cp += bytes;
+               puts(line);
+       }
+       printf("\n");
+       free(data);
+}
+
 #define FIRST_FEW_BYTES 8000
 static int mmfile_is_binary(mmfile_t *mf)
 {
@@ -342,6 +538,7 @@ static void builtin_diff(const char *name_a,
                         struct diff_filespec *one,
                         struct diff_filespec *two,
                         const char *xfrm_msg,
+                        struct diff_options *o,
                         int complete_rewrite)
 {
        mmfile_t mf1, mf2;
@@ -386,8 +583,17 @@ 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 (mmfile_is_binary(&mf1) || mmfile_is_binary(&mf2))
-               printf("Binary files %s and %s differ\n", lbl[0], lbl[1]);
+       if (mmfile_is_binary(&mf1) || mmfile_is_binary(&mf2)) {
+               /* Quite common confusing case */
+               if (mf1.size == mf2.size &&
+                   !memcmp(mf1.ptr, mf2.ptr, mf1.size))
+                       goto free_ab_and_return;
+               if (o->binary)
+                       emit_binary_diff(&mf1, &mf2);
+               else
+                       printf("Binary files %s and %s differ\n",
+                              lbl[0], lbl[1]);
+       }
        else {
                /* Crazy xdl interfaces.. */
                const char *diffopts = getenv("GIT_DIFF_OPTS");
@@ -398,7 +604,7 @@ static void builtin_diff(const char *name_a,
 
                ecbdata.label_path = lbl;
                xpp.flags = XDF_NEED_MINIMAL;
-               xecfg.ctxlen = 3;
+               xecfg.ctxlen = o->context;
                xecfg.flags = XDL_EMIT_FUNCNAMES;
                if (!diffopts)
                        ;
@@ -418,19 +624,32 @@ 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,
+                            int complete_rewrite)
 {
        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;
+               return;
+       }
+       if (complete_rewrite) {
+               diff_populate_filespec(one, 0);
+               diff_populate_filespec(two, 0);
+               data->deleted = count_lines(one->data, one->size);
+               data->added = count_lines(two->data, two->size);
+               return;
+       }
        if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
                die("unable to read files to diff");
 
        if (mmfile_is_binary(&mf1) || mmfile_is_binary(&mf2))
-               data->added = -1;
+               data->is_binary = 1;
        else {
                /* Crazy xdl interfaces.. */
                xpparam_t xpp;
@@ -446,6 +665,41 @@ static void builtin_diffstat(const char *name_a, const char *name_b,
        }
 }
 
+static void builtin_checkdiff(const char *name_a, const char *name_b,
+                            struct diff_filespec *one,
+                            struct diff_filespec *two)
+{
+       mmfile_t mf1, mf2;
+       struct checkdiff_t data;
+
+       if (!two)
+               return;
+
+       memset(&data, 0, sizeof(data));
+       data.xm.consume = checkdiff_consume;
+       data.filename = name_b ? name_b : name_a;
+       data.lineno = 0;
+
+       if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
+               die("unable to read files to diff");
+
+       if (mmfile_is_binary(&mf2))
+               return;
+       else {
+               /* Crazy xdl interfaces.. */
+               xpparam_t xpp;
+               xdemitconf_t xecfg;
+               xdemitcb_t ecb;
+
+               xpp.flags = XDF_NEED_MINIMAL;
+               xecfg.ctxlen = 0;
+               xecfg.flags = 0;
+               ecb.outf = xdiff_outf;
+               ecb.priv = &data;
+               xdl_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
+       }
+}
+
 struct diff_filespec *alloc_filespec(const char *path)
 {
        int namelen = strlen(path);
@@ -850,6 +1104,7 @@ static void run_diff_cmd(const char *pgm,
                         struct diff_filespec *one,
                         struct diff_filespec *two,
                         const char *xfrm_msg,
+                        struct diff_options *o,
                         int complete_rewrite)
 {
        if (pgm) {
@@ -859,7 +1114,7 @@ static void run_diff_cmd(const char *pgm,
        }
        if (one && two)
                builtin_diff(name, other ? other : name,
-                            one, two, xfrm_msg, complete_rewrite);
+                            one, two, xfrm_msg, o, complete_rewrite);
        else
                printf("* Unmerged path %s\n", name);
 }
@@ -893,7 +1148,7 @@ static void run_diff(struct diff_filepair *p, struct diff_options *o)
 
        if (DIFF_PAIR_UNMERGED(p)) {
                /* unmerged */
-               run_diff_cmd(pgm, p->one->path, NULL, NULL, NULL, NULL, 0);
+               run_diff_cmd(pgm, p->one->path, NULL, NULL, NULL, NULL, o, 0);
                return;
        }
 
@@ -940,14 +1195,12 @@ static void run_diff(struct diff_filepair *p, struct diff_options *o)
        }
 
        if (memcmp(one->sha1, two->sha1, 20)) {
-               char one_sha1[41];
                int abbrev = o->full_index ? 40 : DEFAULT_ABBREV;
-               memcpy(one_sha1, sha1_to_hex(one->sha1), 41);
 
                len += snprintf(msg + len, sizeof(msg) - len,
                                "index %.*s..%.*s",
-                               abbrev, one_sha1, abbrev,
-                               sha1_to_hex(two->sha1));
+                               abbrev, sha1_to_hex(one->sha1),
+                               abbrev, sha1_to_hex(two->sha1));
                if (one->mode == two->mode)
                        len += snprintf(msg + len, sizeof(msg) - len,
                                        " %06o", one->mode);
@@ -965,14 +1218,14 @@ static void run_diff(struct diff_filepair *p, struct diff_options *o)
                 * needs to be split into deletion and creation.
                 */
                struct diff_filespec *null = alloc_filespec(two->path);
-               run_diff_cmd(NULL, name, other, one, null, xfrm_msg, 0);
+               run_diff_cmd(NULL, name, other, one, null, xfrm_msg, o, 0);
                free(null);
                null = alloc_filespec(one->path);
-               run_diff_cmd(NULL, name, other, null, two, xfrm_msg, 0);
+               run_diff_cmd(NULL, name, other, null, two, xfrm_msg, o, 0);
                free(null);
        }
        else
-               run_diff_cmd(pgm, name, other, one, two, xfrm_msg,
+               run_diff_cmd(pgm, name, other, one, two, xfrm_msg, o,
                             complete_rewrite);
 
        free(name_munged);
@@ -980,14 +1233,36 @@ 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;
+       int complete_rewrite = 0;
+
+       if (DIFF_PAIR_UNMERGED(p)) {
+               /* unmerged */
+               builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, 0);
+               return;
+       }
+
+       name = p->one->path;
+       other = (strcmp(name, p->two->path) ? p->two->path : NULL);
+
+       diff_fill_sha1_info(p->one);
+       diff_fill_sha1_info(p->two);
+
+       if (p->status == DIFF_STATUS_MODIFIED && p->score)
+               complete_rewrite = 1;
+       builtin_diffstat(name, other, p->one, p->two, diffstat, complete_rewrite);
+}
+
+static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
 {
        const char *name;
        const char *other;
 
        if (DIFF_PAIR_UNMERGED(p)) {
                /* unmerged */
-               builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat);
                return;
        }
 
@@ -997,7 +1272,7 @@ static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
        diff_fill_sha1_info(p->one);
        diff_fill_sha1_info(p->two);
 
-       builtin_diffstat(name, other, p->one, p->two, diffstat);
+       builtin_checkdiff(name, other, p->one, p->two);
 }
 
 void diff_setup(struct diff_options *options)
@@ -1007,6 +1282,7 @@ void diff_setup(struct diff_options *options)
        options->line_termination = '\n';
        options->break_opt = -1;
        options->rename_limit = -1;
+       options->context = 3;
 
        options->change = diff_change;
        options->add_remove = diff_addremove;
@@ -1018,6 +1294,24 @@ int diff_setup_done(struct diff_options *options)
             options->detect_rename != DIFF_DETECT_COPY) ||
            (0 <= options->rename_limit && !options->detect_rename))
                return -1;
+
+       /*
+        * These cases always need recursive; we do not drop caller-supplied
+        * recursive bits for other formats here.
+        */
+       if ((options->output_format == DIFF_FORMAT_PATCH) ||
+           (options->output_format == DIFF_FORMAT_DIFFSTAT) ||
+           (options->output_format == DIFF_FORMAT_CHECKDIFF))
+               options->recursive = 1;
+
+       /*
+        * These combinations do not make sense.
+        */
+       if (options->output_format == DIFF_FORMAT_RAW)
+               options->with_raw = 0;
+       if (options->output_format == DIFF_FORMAT_DIFFSTAT)
+               options->with_stat  = 0;
+
        if (options->detect_rename && options->rename_limit < 0)
                options->rename_limit = diff_rename_limit_default;
        if (options->setup & DIFF_SETUP_USE_CACHE) {
@@ -1038,23 +1332,84 @@ int diff_setup_done(struct diff_options *options)
        return 0;
 }
 
+int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
+{
+       char c, *eq;
+       int len;
+
+       if (*arg != '-')
+               return 0;
+       c = *++arg;
+       if (!c)
+               return 0;
+       if (c == arg_short) {
+               c = *++arg;
+               if (!c)
+                       return 1;
+               if (val && isdigit(c)) {
+                       char *end;
+                       int n = strtoul(arg, &end, 10);
+                       if (*end)
+                               return 0;
+                       *val = n;
+                       return 1;
+               }
+               return 0;
+       }
+       if (c != '-')
+               return 0;
+       arg++;
+       eq = strchr(arg, '=');
+       if (eq)
+               len = eq - arg;
+       else
+               len = strlen(arg);
+       if (!len || strncmp(arg, arg_long, len))
+               return 0;
+       if (eq) {
+               int n;
+               char *end;
+               if (!isdigit(*++eq))
+                       return 0;
+               n = strtoul(eq, &end, 10);
+               if (*end)
+                       return 0;
+               *val = n;
+       }
+       return 1;
+}
+
 int diff_opt_parse(struct diff_options *options, const char **av, int ac)
 {
        const char *arg = av[0];
        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, "--patch-with-raw")) {
                options->output_format = DIFF_FORMAT_PATCH;
                options->with_raw = 1;
        }
        else if (!strcmp(arg, "--stat"))
                options->output_format = DIFF_FORMAT_DIFFSTAT;
+       else if (!strcmp(arg, "--check"))
+               options->output_format = DIFF_FORMAT_CHECKDIFF;
+       else if (!strcmp(arg, "--summary"))
+               options->summary = 1;
+       else if (!strcmp(arg, "--patch-with-stat")) {
+               options->output_format = DIFF_FORMAT_PATCH;
+               options->with_stat = 1;
+       }
        else if (!strcmp(arg, "-z"))
                options->line_termination = 0;
        else if (!strncmp(arg, "-l", 2))
                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->full_index = options->binary = 1;
+       }
        else if (!strcmp(arg, "--name-only"))
                options->output_format = DIFF_FORMAT_NAME;
        else if (!strcmp(arg, "--name-status"))
@@ -1349,7 +1704,7 @@ 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;
@@ -1361,6 +1716,19 @@ static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
        run_diffstat(p, o, diffstat);
 }
 
+static void diff_flush_checkdiff(struct diff_filepair *p,
+               struct diff_options *o)
+{
+       if (diff_unmodified_pair(p))
+               return;
+
+       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 */
+
+       run_checkdiff(p, o);
+}
+
 int diff_queue_is_empty(void)
 {
        struct diff_queue_struct *q = &diff_queued_diff;
@@ -1491,6 +1859,9 @@ static void flush_one_pair(struct diff_filepair *p,
                case DIFF_FORMAT_DIFFSTAT:
                        diff_flush_stat(p, options, diffstat);
                        break;
+               case DIFF_FORMAT_CHECKDIFF:
+                       diff_flush_checkdiff(p, options);
+                       break;
                case DIFF_FORMAT_PATCH:
                        diff_flush_patch(p, options);
                        break;
@@ -1511,6 +1882,85 @@ static void flush_one_pair(struct diff_filepair *p,
        }
 }
 
+static void show_file_mode_name(const char *newdelete, struct diff_filespec *fs)
+{
+       if (fs->mode)
+               printf(" %s mode %06o %s\n", newdelete, fs->mode, fs->path);
+       else
+               printf(" %s %s\n", newdelete, fs->path);
+}
+
+
+static void show_mode_change(struct diff_filepair *p, int show_name)
+{
+       if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
+               if (show_name)
+                       printf(" mode change %06o => %06o %s\n",
+                              p->one->mode, p->two->mode, p->two->path);
+               else
+                       printf(" mode change %06o => %06o\n",
+                              p->one->mode, p->two->mode);
+       }
+}
+
+static void show_rename_copy(const char *renamecopy, struct diff_filepair *p)
+{
+       const char *old, *new;
+
+       /* Find common prefix */
+       old = p->one->path;
+       new = p->two->path;
+       while (1) {
+               const char *slash_old, *slash_new;
+               slash_old = strchr(old, '/');
+               slash_new = strchr(new, '/');
+               if (!slash_old ||
+                   !slash_new ||
+                   slash_old - old != slash_new - new ||
+                   memcmp(old, new, slash_new - new))
+                       break;
+               old = slash_old + 1;
+               new = slash_new + 1;
+       }
+       /* p->one->path thru old is the common prefix, and old and new
+        * through the end of names are renames
+        */
+       if (old != p->one->path)
+               printf(" %s %.*s{%s => %s} (%d%%)\n", renamecopy,
+                      (int)(old - p->one->path), p->one->path,
+                      old, new, (int)(0.5 + p->score * 100.0/MAX_SCORE));
+       else
+               printf(" %s %s => %s (%d%%)\n", renamecopy,
+                      p->one->path, p->two->path,
+                      (int)(0.5 + p->score * 100.0/MAX_SCORE));
+       show_mode_change(p, 0);
+}
+
+static void diff_summary(struct diff_filepair *p)
+{
+       switch(p->status) {
+       case DIFF_STATUS_DELETED:
+               show_file_mode_name("delete", p->one);
+               break;
+       case DIFF_STATUS_ADDED:
+               show_file_mode_name("create", p->two);
+               break;
+       case DIFF_STATUS_COPIED:
+               show_rename_copy("copy", p);
+               break;
+       case DIFF_STATUS_RENAMED:
+               show_rename_copy("rename", p);
+               break;
+       default:
+               if (p->score) {
+                       printf(" rewrite %s (%d%%)\n", p->two->path,
+                               (int)(0.5 + p->score * 100.0/MAX_SCORE));
+                       show_mode_change(p, 0);
+               } else  show_mode_change(p, 1);
+               break;
+       }
+}
+
 void diff_flush(struct diff_options *options)
 {
        struct diff_queue_struct *q = &diff_queued_diff;
@@ -1518,7 +1968,7 @@ void diff_flush(struct diff_options *options)
        int diff_output_format = options->output_format;
        struct diffstat_t *diffstat = NULL;
 
-       if (diff_output_format == DIFF_FORMAT_DIFFSTAT) {
+       if (diff_output_format == DIFF_FORMAT_DIFFSTAT || options->with_stat) {
                diffstat = xcalloc(sizeof (struct diffstat_t), 1);
                diffstat->xm.consume = diffstat_consume;
        }
@@ -1530,10 +1980,26 @@ void diff_flush(struct diff_options *options)
                }
                putchar(options->line_termination);
        }
+       if (options->with_stat) {
+               for (i = 0; i < q->nr; i++) {
+                       struct diff_filepair *p = q->queue[i];
+                       flush_one_pair(p, DIFF_FORMAT_DIFFSTAT, options,
+                                      diffstat);
+               }
+               show_stats(diffstat);
+               free(diffstat);
+               diffstat = NULL;
+               if (options->summary)
+                       for (i = 0; i < q->nr; i++)
+                               diff_summary(q->queue[i]);
+               if (options->stat_sep)
+                       fputs(options->stat_sep, stdout);
+               else
+                       putchar(options->line_termination);
+       }
        for (i = 0; i < q->nr; i++) {
                struct diff_filepair *p = q->queue[i];
                flush_one_pair(p, diff_output_format, options, diffstat);
-               diff_free_filepair(p);
        }
 
        if (diffstat) {
@@ -1541,6 +2007,12 @@ void diff_flush(struct diff_options *options)
                free(diffstat);
        }
 
+       for (i = 0; i < q->nr; i++) {
+               if (diffstat && options->summary)
+                       diff_summary(q->queue[i]);
+               diff_free_filepair(q->queue[i]);
+       }
+
        free(q->queue);
        q->queue = NULL;
        q->nr = q->alloc = 0;