[PATCH] Fix diff-pruning logic which was running prune too early.
[git.git] / diff.c
diff --git a/diff.c b/diff.c
index 5a2aee7..05e5277 100644 (file)
--- a/diff.c
+++ b/diff.c
@@ -12,9 +12,6 @@ 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 const char *external_diff(void)
 {
@@ -502,7 +499,9 @@ struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
        return dp;
 }
 
-static void diff_flush_raw(struct diff_filepair *p)
+static void diff_flush_raw(struct diff_filepair *p,
+                          int line_termination,
+                          int inter_name_termination)
 {
        int two_paths;
        char status[10];
@@ -566,10 +565,6 @@ static void diff_flush_patch(struct diff_filepair *p)
        const char *name, *other;
        char msg_[PATH_MAX*2+200], *msg;
 
-       /* diffcore_prune() keeps "stay" entries for diff-raw
-        * copy/rename detection, but when we are generating
-        * patches we do not need them.
-        */
        if (diff_unmodified_pair(p))
                return;
 
@@ -585,7 +580,7 @@ static void diff_flush_patch(struct diff_filepair *p)
                        "similarity index %d%%\n"
                        "copy from %s\n"
                        "copy to %s\n",
-                       (int)(0.5 + p->score * 100/MAX_SCORE),
+                       (int)(0.5 + p->score * 100.0/MAX_SCORE),
                        p->one->path, p->two->path);
                msg = msg_;
                break;
@@ -594,7 +589,7 @@ static void diff_flush_patch(struct diff_filepair *p)
                        "similarity index %d%%\n"
                        "rename old %s\n"
                        "rename new %s\n",
-                       (int)(0.5 + p->score * 100/MAX_SCORE),
+                       (int)(0.5 + p->score * 100.0/MAX_SCORE),
                        p->one->path, p->two->path);
                msg = msg_;
                break;
@@ -630,105 +625,82 @@ int diff_needs_to_stay(struct diff_queue_struct *q, int i,
        return 0;
 }
 
-static int diff_used_as_source(struct diff_queue_struct *q, int lim,
-                              struct diff_filespec *it)
+int diff_queue_is_empty(void)
 {
-       int i;
-       for (i = 0; i < lim; i++) {
-               struct diff_filepair *p = q->queue[i++];
-               if (!strcmp(p->one->path, it->path))
-                       return 1;
-       }
-       return 0;
+       struct diff_queue_struct *q = &diff_queued_diff;
+       return q->nr == 0;
 }
 
-void diffcore_prune(void)
+static void diff_resolve_rename_copy(void)
 {
-       /*
-        * Although rename/copy detection wants to have "no-change"
-        * entries fed into them, the downstream do not need to see
-        * them, unless we had rename/copy for the same path earlier.
-        * 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.
-        * (5) call diff_flush().
-        */
-       struct diff_queue_struct *q = &diff_queued_diff;
-       struct diff_queue_struct outq;
        int i;
-
-       outq.queue = NULL;
-       outq.nr = outq.alloc = 0;
-
+       struct diff_queue_struct *q = &diff_queued_diff;
        for (i = 0; i < q->nr; i++) {
                struct diff_filepair *p = q->queue[i];
-               if (!diff_unmodified_pair(p) ||
-                   diff_used_as_source(q, i, p->one))
-                       diff_q(&outq, p);
-               else
-                       free(p);
+               p->status = 0;
+               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)) {
+                       /* maybe earlier one said 'R', meaning
+                        * it will take it, in which case we do
+                        * not need to keep 'D'.
+                        */
+                       int j;
+                       for (j = 0; j < i; j++) {
+                               struct diff_filepair *pp = q->queue[j];
+                               if (pp->status == 'R' &&
+                                   !strcmp(pp->one->path, p->one->path))
+                                       break;
+                       }
+                       if (j < i)
+                               continue;
+                       p->status = 'D';
+               }
+               else if (strcmp(p->one->path, p->two->path)) {
+                       /* This is rename or copy.  Which one is it? */
+                       if (diff_needs_to_stay(q, i+1, p->one))
+                               p->status = 'C';
+                       else
+                               p->status = 'R';
+               }
+               else if (memcmp(p->one->sha1, p->two->sha1, 20))
+                       p->status = 'M';
+               else {
+                       /* we do not need this one */
+                       p->status = 0;
+               }
        }
-       free(q->queue);
-       *q = outq;
-       return;
-}
-
-int diff_queue_is_empty(void)
-{
-       struct diff_queue_struct *q = &diff_queued_diff;
-       return q->nr == 0;
 }
 
 void diff_flush(int diff_output_style, int resolve_rename_copy)
 {
        struct diff_queue_struct *q = &diff_queued_diff;
        int i;
+       int line_termination = '\n';
+       int inter_name_termination = '\t';
 
-       generate_patch = 0;
-       switch (diff_output_style) {
-       case DIFF_FORMAT_HUMAN:
-               line_termination = '\n';
-               inter_name_termination = '\t';
-               break;
-       case DIFF_FORMAT_MACHINE:
+       if (diff_output_style == DIFF_FORMAT_MACHINE)
                line_termination = inter_name_termination = 0;
-               break;
-       case DIFF_FORMAT_PATCH:
-               generate_patch = 1;
-               break;
-       }
+       if (resolve_rename_copy)
+               diff_resolve_rename_copy();
+
        for (i = 0; i < q->nr; i++) {
                struct diff_filepair *p = q->queue[i];
-               if (resolve_rename_copy) {
-                       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 (strcmp(p->one->path, p->two->path)) {
-                               /* This is rename or copy.  Which one is it? */
-                               if (diff_needs_to_stay(q, i+1, p->one))
-                                       p->status = 'C';
-                               else
-                                       p->status = 'R';
-                       }
-                       else
-                               p->status = 'M';
-               }
-               if (generate_patch)
+               if (p->status == 0)
+                       continue;
+               switch (diff_output_style) {
+               case DIFF_FORMAT_PATCH:
                        diff_flush_patch(p);
-               else
-                       diff_flush_raw(p);
+                       break;
+               case DIFF_FORMAT_HUMAN:
+               case DIFF_FORMAT_MACHINE:
+                       diff_flush_raw(p, line_termination,
+                                      inter_name_termination);
+                       break;
+               }
        }
-
        for (i = 0; i < q->nr; i++) {
                struct diff_filepair *p = q->queue[i];
                diff_free_filespec_data(p->one);
@@ -755,9 +727,9 @@ void diff_addremove(int addremove, unsigned mode,
         * with something like '=' or '*' (I haven't decided
         * which but should not make any difference).
         * Feeding the same new and old to diff_change() 
-        * also has the same effect.  diffcore_prune() should
-        * be used to filter uninteresting ones out before the
-        * final output happens.
+        * 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 == '+' ? '-' :