Merge master.kernel.org:/pub/scm/gitk/gitk
[gitweb.git] / diff.c
diff --git a/diff.c b/diff.c
index 4757547ea00f57a6523f0300be24b1c8bcde316e..3cb41c533313fdd70b3f13858c68032aeb08062a 100644 (file)
--- a/diff.c
+++ b/diff.c
@@ -5,6 +5,7 @@
 #include <sys/wait.h>
 #include <signal.h>
 #include "cache.h"
+#include "quote.h"
 #include "diff.h"
 #include "diffcore.h"
 
@@ -12,9 +13,7 @@ static const char *diff_opts = "-pu";
 static unsigned char null_sha1[20] = { 0, };
 
 static int reverse_diff;
-static int generate_patch;
-static int line_termination = '\n';
-static int inter_name_termination = '\t';
+static int use_size_cache;
 
 static const char *external_diff(void)
 {
@@ -42,42 +41,6 @@ static const char *external_diff(void)
        return external_diff_cmd;
 }
 
-/* Help to copy the thing properly quoted for the shell safety.
- * any single quote is replaced with '\'', and the caller is
- * expected to enclose the result within a single quote pair.
- *
- * E.g.
- *  original     sq_expand     result
- *  name     ==> name      ==> 'name'
- *  a b      ==> a b       ==> 'a b'
- *  a'b      ==> a'\''b    ==> 'a'\''b'
- */
-static char *sq_expand(const char *src)
-{
-       static char *buf = NULL;
-       int cnt, c;
-       const char *cp;
-       char *bp;
-
-       /* count bytes needed to store the quoted string. */
-       for (cnt = 1, cp = src; *cp; cnt++, cp++)
-               if (*cp == '\'')
-                       cnt += 3;
-
-       buf = xmalloc(cnt);
-       bp = buf;
-       while ((c = *src++)) {
-               if (c != '\'')
-                       *bp++ = c;
-               else {
-                       bp = strcpy(bp, "'\\''");
-                       bp += 4;
-               }
-       }
-       *bp = 0;
-       return buf;
-}
-
 static struct diff_tempfile {
        const char *name; /* filename external diff should read from */
        char hex[41];
@@ -85,22 +48,100 @@ 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'";
-       const char *diff_arg  = "'%s' '%s'||:"; /* "||:" is to return 0 */
+       const char *diff_cmd = "diff -L%s%s -L%s%s";
+       const char *diff_arg  = "%s %s||:"; /* "||:" is to return 0 */
        const char *input_name_sq[2];
        const char *path0[2];
        const char *path1[2];
        const char *name_sq[2];
        char *cmd;
 
-       name_sq[0] = sq_expand(name_a);
-       name_sq[1] = sq_expand(name_b);
+       name_sq[0] = sq_quote(name_a);
+       name_sq[1] = sq_quote(name_b);
 
        /* diff_cmd and diff_arg have 6 %s in total which makes
         * the sum of these strings 12 bytes larger than required.
@@ -110,7 +151,7 @@ static void builtin_diff(const char *name_a,
        cmd_size = (strlen(diff_cmd) + strlen(diff_opts) +
                        strlen(diff_arg) - 9);
        for (i = 0; i < 2; i++) {
-               input_name_sq[i] = sq_expand(temp[i].name);
+               input_name_sq[i] = sq_quote(temp[i].name);
                if (!strcmp(temp[i].name, "/dev/null")) {
                        path0[i] = "/dev/null";
                        path1[i] = "";
@@ -134,23 +175,33 @@ 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);
                        printf("new mode %s\n", temp[1].mode);
                }
                if (xfrm_msg && xfrm_msg[0])
-                       fputs(xfrm_msg, stdout);
-
+                       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);
@@ -165,7 +216,7 @@ struct diff_filespec *alloc_filespec(const char *path)
        spec->should_free = spec->should_munmap = 0;
        spec->xfrm_flags = 0;
        spec->size = 0;
-       spec->data = 0;
+       spec->data = NULL;
        spec->mode = 0;
        memset(spec->sha1, 0, 20);
        return spec;
@@ -174,8 +225,8 @@ struct diff_filespec *alloc_filespec(const char *path)
 void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
                   unsigned short mode)
 {
-       if (mode) { /* just playing defensive */
-               spec->mode = mode;
+       if (mode) {
+               spec->mode = DIFF_FILE_CANON_MODE(mode);
                memcpy(spec->sha1, sha1, 20);
                spec->sha1_valid = !!memcmp(sha1, null_sha1, 20);
        }
@@ -225,12 +276,61 @@ static int work_tree_matches(const char *name, const unsigned char *sha1)
        return 1;
 }
 
+static struct sha1_size_cache {
+       unsigned char sha1[20];
+       unsigned long size;
+} **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;
+       struct sha1_size_cache *e;
+
+       first = 0;
+       last = sha1_size_cache_nr;
+       while (last > first) {
+               int cmp, next = (last + first) >> 1;
+               e = sha1_size_cache[next];
+               cmp = memcmp(e->sha1, sha1, 20);
+               if (!cmp)
+                       return e;
+               if (cmp < 0) {
+                       last = next;
+                       continue;
+               }
+               first = next+1;
+       }
+       /* not found */
+       if (find_only)
+               return NULL;
+       /* insert to make it at "first" */
+       if (sha1_size_cache_alloc <= sha1_size_cache_nr) {
+               sha1_size_cache_alloc = alloc_nr(sha1_size_cache_alloc);
+               sha1_size_cache = xrealloc(sha1_size_cache,
+                                          sha1_size_cache_alloc *
+                                          sizeof(*sha1_size_cache));
+       }
+       sha1_size_cache_nr++;
+       if (first < sha1_size_cache_nr)
+               memmove(sha1_size_cache + first + 1, sha1_size_cache + first,
+                       (sha1_size_cache_nr - first - 1) *
+                       sizeof(*sha1_size_cache));
+       e = xmalloc(sizeof(struct sha1_size_cache));
+       sha1_size_cache[first] = e;
+       memcpy(e->sha1, sha1, 20);
+       e->size = size;
+       return e;
+}
+
 /*
  * While doing rename detection and pickaxe operation, we may need to
  * grab the data for the blob (or file) for our own in-core comparison.
  * diff_filespec has data and size fields for this purpose.
  */
-int diff_populate_filespec(struct diff_filespec *s)
+int diff_populate_filespec(struct diff_filespec *s, int size_only)
 {
        int err = 0;
        if (!DIFF_FILE_VALID(s))
@@ -238,6 +338,9 @@ int diff_populate_filespec(struct diff_filespec *s)
        if (S_ISDIR(s->mode))
                return -1;
 
+       if (!use_size_cache)
+               size_only = 0;
+
        if (s->data)
                return err;
        if (!s->sha1_valid ||
@@ -257,6 +360,8 @@ int diff_populate_filespec(struct diff_filespec *s)
                s->size = st.st_size;
                if (!s->size)
                        goto empty;
+               if (size_only)
+                       return 0;
                if (S_ISLNK(st.st_mode)) {
                        int ret;
                        s->data = xmalloc(s->size);
@@ -277,18 +382,25 @@ int diff_populate_filespec(struct diff_filespec *s)
        }
        else {
                char type[20];
-               s->data = read_sha1_file(s->sha1, type, &s->size);
-               s->should_free = 1;
+               struct sha1_size_cache *e;
+
+               if (size_only) {
+                       e = locate_size_cache(s->sha1, 1, 0);
+                       if (e) {
+                               s->size = e->size;
+                               return 0;
+                       }
+                       if (!sha1_object_info(s->sha1, type, &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;
+               }
        }
        return 0;
 }
 
-void diff_free_filepair(struct diff_filepair *p)
-{
-       free(p->xfrm_msg);
-       free(p);
-}
-
 void diff_free_filespec_data(struct diff_filespec *s)
 {
        if (s->should_free)
@@ -296,7 +408,7 @@ void diff_free_filespec_data(struct diff_filespec *s)
        else if (s->should_munmap)
                munmap(s->data, s->size);
        s->should_free = s->should_munmap = 0;
-       s->data = 0;
+       s->data = NULL;
 }
 
 static void prep_temp_blob(struct diff_tempfile *temp,
@@ -364,13 +476,18 @@ static void prepare_temp_file(const char *name,
                                strcpy(temp->hex, sha1_to_hex(null_sha1));
                        else
                                strcpy(temp->hex, sha1_to_hex(one->sha1));
-                       sprintf(temp->mode, "%06o",
-                               S_IFREG |ce_permissions(st.st_mode));
+                       /* Even though we may sometimes borrow the
+                        * contents from the work tree, we always want
+                        * one->mode.  mode is trustworthy even when
+                        * !(one->sha1_valid), as long as
+                        * DIFF_FILE_VALID(one).
+                        */
+                       sprintf(temp->mode, "%06o", one->mode);
                }
                return;
        }
        else {
-               if (diff_populate_filespec(one))
+               if (diff_populate_filespec(one, 0))
                        die("cannot read data blob for %s", one->path);
                prep_temp_blob(temp, one->data, one->size,
                               one->sha1, one->mode);
@@ -399,11 +516,13 @@ static void remove_tempfile_on_signal(int signo)
  *               infile2 infile2-sha1 infile2-mode [ rename-to ]
  *
  */
-static void run_external_diff(const char *name,
+static void run_external_diff(const char *pgm,
+                             const char *name,
                              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;
@@ -427,7 +546,6 @@ static void run_external_diff(const char *name,
        if (pid < 0)
                die("unable to fork");
        if (!pid) {
-               const char *pgm = external_diff();
                if (pgm) {
                        if (one && two) {
                                const char *exec_arg[10];
@@ -444,7 +562,7 @@ static void run_external_diff(const char *name,
                                        *arg++ = other;
                                        *arg++ = xfrm_msg;
                                }
-                               *arg = 0;
+                               *arg = NULL;
                                execvp(pgm, (char *const*) exec_arg);
                        }
                        else
@@ -454,7 +572,8 @@ static void run_external_diff(const char *name,
                 * 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);
@@ -477,9 +596,145 @@ static void run_external_diff(const char *name,
        remove_tempfile();
 }
 
-void diff_setup(int reverse_diff_)
+static void run_diff(struct diff_filepair *p)
 {
-       reverse_diff = reverse_diff_;
+       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)) {
+               /* a filepair that changes between file and symlink
+                * 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, 0);
+               free(null);
+               null = alloc_filespec(one->path);
+               run_external_diff(NULL, name, other, null, two, xfrm_msg, 0);
+               free(null);
+       }
+       else
+               run_external_diff(pgm, name, other, one, two, xfrm_msg,
+                                 complete_rewrite);
+}
+
+void diff_setup(int flags)
+{
+       if (flags & DIFF_SETUP_REVERSE)
+               reverse_diff = 1;
+       if (flags & DIFF_SETUP_USE_CACHE) {
+               if (!active_cache)
+                       /* read-cache does not die even when it fails
+                        * so it is safe for us to do this here.  Also
+                        * it does not smudge active_cache or active_nr
+                        * when it fails, so we do not have to worry about
+                        * cleaning it up oufselves either.
+                        */
+                       read_cache();
+       }
+       if (flags & DIFF_SETUP_USE_SIZE_CACHE)
+               use_size_cache = 1;
+       
+}
+
+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;
@@ -501,44 +756,75 @@ struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
        struct diff_filepair *dp = xmalloc(sizeof(*dp));
        dp->one = one;
        dp->two = two;
-       dp->xfrm_msg = 0;
-       dp->orig_order = queue->nr;
-       dp->xfrm_work = 0;
+       dp->score = 0;
+       dp->status = 0;
+       dp->source_stays = 0;
+       dp->broken_pair = 0;
        diff_q(queue, dp);
        return dp;
 }
 
-static void diff_flush_raw(struct diff_filepair *p)
+void diff_free_filepair(struct diff_filepair *p)
 {
-       if (DIFF_PAIR_UNMERGED(p)) {
-               printf("U %s%c", p->one->path, line_termination);
-               return;
+       diff_free_filespec_data(p->one);
+       diff_free_filespec_data(p->two);
+       free(p);
+}
+
+static void diff_flush_raw(struct diff_filepair *p,
+                          int line_termination,
+                          int inter_name_termination)
+{
+       int two_paths;
+       char status[10];
+
+       if (line_termination) {
+               const char *err = "path %s cannot be expressed without -z";
+               if (strchr(p->one->path, line_termination) ||
+                   strchr(p->one->path, inter_name_termination))
+                       die(err, p->one->path);
+               if (strchr(p->two->path, line_termination) ||
+                   strchr(p->two->path, inter_name_termination))
+                       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;
+               break;
+       case 'N': case 'D':
+               two_paths = 0;
+               break;
+       default:
+               two_paths = 0;
+               break;
        }
        printf(":%06o %06o %s ",
               p->one->mode, p->two->mode, sha1_to_hex(p->one->sha1));
-       printf("%s%c%s%c%s%c",
-              sha1_to_hex(p->two->sha1), inter_name_termination,
-              p->one->path, inter_name_termination,
-              p->two->path, line_termination);
+       printf("%s %s%c%s",
+              sha1_to_hex(p->two->sha1),
+              status,
+              inter_name_termination,
+              p->one->path);
+       if (two_paths)
+               printf("%c%s", inter_name_termination, p->two->path);
+       putchar(line_termination);
 }
 
-static void diff_flush_patch(struct diff_filepair *p)
+static void diff_flush_name(struct diff_filepair *p,
+                           int line_termination)
 {
-       const char *name, *other;
-
-       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 */ 
-
-       if (DIFF_PAIR_UNMERGED(p))
-               run_external_diff(name, NULL, NULL, NULL, NULL);
-       else
-               run_external_diff(name, other, p->one, p->two, p->xfrm_msg);
+       printf("%s%c", p->two->path, line_termination);
 }
 
-static int uninteresting(struct diff_filepair *p)
+int diff_unmodified_pair(struct diff_filepair *p)
 {
        /* This function is written stricter than necessary to support
         * the currently implemented transformers, but the idea is to
@@ -553,9 +839,11 @@ static int uninteresting(struct diff_filepair *p)
        one = p->one;
        two = p->two;
 
-       /* deletion, addition, mode change and renames are all interesting. */
+       /* deletion, addition, mode or type change
+        * and rename are all interesting.
+        */
        if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
-           (one->mode != two->mode) ||
+           DIFF_PAIR_MODE_CHANGED(p) ||
            strcmp(one->path, two->path))
                return 0;
 
@@ -570,94 +858,247 @@ static int uninteresting(struct diff_filepair *p)
        return 0;
 }
 
-void diffcore_prune(void)
+static void diff_flush_patch(struct diff_filepair *p)
+{
+       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_diff(p);
+}
+
+int diff_queue_is_empty(void)
 {
-       /*
-        * Although rename/copy detection wants to have "no-change"
-        * entries fed into them, the downstream do not need to see
-        * them.  This function removes such entries.
-        *
-        * The applications that use rename/copy should:
-        *
-        * (1) feed change and "no-change" entries via diff_queue().
-        * (2) call diffcore_rename, and any other future diffcore_xxx
-        *     that would benefit by still having "no-change" entries.
-        * (3) call diffcore_prune
-        * (4) call other diffcore_xxx that do not need to see
-        *     "no-change" entries.
-        */
        struct diff_queue_struct *q = &diff_queued_diff;
-       struct diff_queue_struct outq;
        int i;
+       for (i = 0; i < q->nr; i++)
+               if (!diff_unmodified_pair(q->queue[i]))
+                       return 0;
+       return 1;
+}
 
-       outq.queue = NULL;
-       outq.nr = outq.alloc = 0;
+#if DIFF_DEBUG
+void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
+{
+       fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
+               x, one ? : "",
+               s->path,
+               DIFF_FILE_VALID(s) ? "valid" : "invalid",
+               s->mode,
+               s->sha1_valid ? sha1_to_hex(s->sha1) : "");
+       fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
+               x, one ? : "",
+               s->size, s->xfrm_flags);
+}
+
+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 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)
+{
+       int i;
+       if (msg)
+               fprintf(stderr, "%s\n", msg);
+       fprintf(stderr, "q->nr = %d\n", q->nr);
        for (i = 0; i < q->nr; i++) {
                struct diff_filepair *p = q->queue[i];
-               if (!uninteresting(p))
-                       diff_q(&outq, p);
-               else
-                       diff_free_filepair(p);
+               diff_debug_filepair(p, i);
        }
-       free(q->queue);
-       *q = outq;
-       return;
 }
+#endif
 
-static void diff_flush_one(struct diff_filepair *p)
+static void diff_resolve_rename_copy(void)
 {
-       if (uninteresting(p))
-               return;
-       if (generate_patch)
-               diff_flush_patch(p);
-       else
-               diff_flush_raw(p);
+       int i, j;
+       struct diff_filepair *p, *pp;
+       struct diff_queue_struct *q = &diff_queued_diff;
+
+       diff_debug_queue("resolve-rename-copy", q);
+
+       for (i = 0; i < q->nr; i++) {
+               p = q->queue[i];
+               p->status = 0; /* undecided */
+               if (DIFF_PAIR_UNMERGED(p))
+                       p->status = 'U';
+               else if (!DIFF_FILE_VALID(p->one))
+                       p->status = 'N';
+               else if (!DIFF_FILE_VALID(p->two))
+                       p->status = 'D';
+               else if (DIFF_PAIR_TYPE_CHANGED(p))
+                       p->status = 'T';
+
+               /* from this point on, we are dealing with a pair
+                * whose both sides are valid and of the same type, i.e.
+                * either in-place edit or rename/copy edit.
+                */
+               else if (DIFF_PAIR_RENAME(p)) {
+                       if (p->source_stays) {
+                               p->status = 'C';
+                               continue;
+                       }
+                       /* See if there is some other filepair that
+                        * copies from the same source as us.  If so
+                        * we are a copy.  Otherwise we are a rename.
+                        */
+                       for (j = i + 1; j < q->nr; j++) {
+                               pp = q->queue[j];
+                               if (strcmp(pp->one->path, p->one->path))
+                                       continue; /* not us */
+                               if (!DIFF_PAIR_RENAME(pp))
+                                       continue; /* not a rename/copy */
+                               /* pp is a rename/copy from the same source */
+                               p->status = 'C';
+                               break;
+                       }
+                       if (!p->status)
+                               p->status = 'R';
+               }
+               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 and should not
+                        * happen anymore, but prepare for broken callers.
+                        */
+                       error("feeding unmodified %s to diffcore",
+                             p->one->path);
+                       p->status = 'X';
+               }
+       }
+       diff_debug_queue("resolve-rename-copy done", q);
 }
 
-int diff_queue_is_empty(void)
+void diff_flush(int diff_output_style, int line_termination)
 {
        struct diff_queue_struct *q = &diff_queued_diff;
        int i;
+       int inter_name_termination = '\t';
+
+       if (!line_termination)
+               inter_name_termination = 0;
 
        for (i = 0; i < q->nr; i++) {
                struct diff_filepair *p = q->queue[i];
-               if (!uninteresting(p))
-                       return 0;
+               if ((diff_output_style == DIFF_FORMAT_NO_OUTPUT) ||
+                   (p->status == 'X'))
+                       continue;
+               if (p->status == 0)
+                       die("internal error in diff-resolve-rename-copy");
+               switch (diff_output_style) {
+               case DIFF_FORMAT_PATCH:
+                       diff_flush_patch(p);
+                       break;
+               case DIFF_FORMAT_RAW:
+                       diff_flush_raw(p, line_termination,
+                                      inter_name_termination);
+                       break;
+               case DIFF_FORMAT_NAME:
+                       diff_flush_name(p, line_termination);
+                       break;
+               }
        }
-       return 1;
+       for (i = 0; i < q->nr; i++)
+               diff_free_filepair(q->queue[i]);
+       free(q->queue);
+       q->queue = NULL;
+       q->nr = q->alloc = 0;
 }
 
-void diff_flush(int diff_output_style)
+static void diffcore_apply_filter(const char *filter)
 {
-       struct diff_queue_struct *q = &diff_queued_diff;
        int i;
+       struct diff_queue_struct *q = &diff_queued_diff;
+       struct diff_queue_struct outq;
+       outq.queue = NULL;
+       outq.nr = outq.alloc = 0;
 
-       generate_patch = 0;
-       switch (diff_output_style) {
-       case DIFF_FORMAT_HUMAN:
-               line_termination = '\n';
-               inter_name_termination = '\t';
-               break;
-       case DIFF_FORMAT_MACHINE:
-               line_termination = inter_name_termination = 0;
-               break;
-       case DIFF_FORMAT_PATCH:
-               generate_patch = 1;
-               break;
+       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]);
        }
-       for (i = 0; i < q->nr; i++)
-               diff_flush_one(q->queue[i]);
-       for (i = 0; i < q->nr; i++) {
-               struct diff_filepair *p = q->queue[i];
-               diff_free_filespec_data(p->one);
-               diff_free_filespec_data(p->two);
-               free(p->xfrm_msg);
-               free(p);
+       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->queue = NULL;
-       q->nr = q->alloc = 0;
+       *q = outq;
+}
+
+void diffcore_std(const char **paths,
+                 int detect_rename, int rename_score,
+                 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,
@@ -674,10 +1115,10 @@ void diff_addremove(int addremove, unsigned mode,
         * entries to the diff-core.  They will be prefixed
         * with something like '=' or '*' (I haven't decided
         * which but should not make any difference).
-        * Feeding the same new and old to diff_change() should
-        * also have the same effect.  diff_flush() should
-        * filter uninteresting ones out at the final output
-        * stage.
+        * Feeding the same new and old to diff_change() 
+        * also has the same effect.
+        * Before the final output happens, they are pruned after
+        * merged into rename/copy pairs as appropriate.
         */
        if (reverse_diff)
                addremove = (addremove == '+' ? '-' :
@@ -696,28 +1137,27 @@ void diff_addremove(int addremove, unsigned mode,
        diff_queue(&diff_queued_diff, one, two);
 }
 
-void diff_guif(unsigned old_mode,
-              unsigned new_mode,
-              const unsigned char *old_sha1,
-              const unsigned char *new_sha1,
-              const char *old_path,
-              const char *new_path)
+void diff_helper_input(unsigned old_mode,
+                      unsigned new_mode,
+                      const unsigned char *old_sha1,
+                      const unsigned char *new_sha1,
+                      const char *old_path,
+                      int status,
+                      int score,
+                      const char *new_path)
 {
        struct diff_filespec *one, *two;
+       struct diff_filepair *dp;
 
-       if (reverse_diff) {
-               unsigned tmp;
-               const unsigned char *tmp_c;
-               tmp = old_mode; old_mode = new_mode; new_mode = tmp;
-               tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
-       }
        one = alloc_filespec(old_path);
        two = alloc_filespec(new_path);
        if (old_mode)
                fill_filespec(one, old_sha1, old_mode);
        if (new_mode)
                fill_filespec(two, new_sha1, new_mode);
-       diff_queue(&diff_queued_diff, one, two);
+       dp = diff_queue(&diff_queued_diff, one, two);
+       dp->score = score * MAX_SCORE / 100;
+       dp->status = status;
 }
 
 void diff_change(unsigned old_mode, unsigned new_mode,