[PATCH] Fix type-change handling when assigning the status code to filepairs.

The interim single-liner '?' fix resulted delete entries that
should not have emitted coming out in the output as an
unintended side effect; I caught this with the "rename" test in
the test suite.  This patch instead fixes the code that assigns
the status code to each filepair.

I verified this does not break the testcase in udev.git tree Kay
Sievers gave us, by running git-diff-tree on that tree which
showed 21 file to symlink changes.

Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/diff.c b/diff.c
index 3d86b7a..8e3f495 100644 (file)
--- a/diff.c
+++ b/diff.c
@@ -691,27 +691,34 @@ static void diff_resolve_rename_copy(void)
 
        for (i = 0; i < q->nr; i++) {
                p = q->queue[i];
-               p->status = 0;
+               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)) {
                        /* Deletion record should be omitted if there
-                        * is another entry that is a rename or a copy
-                        * and it uses this one as the source.  Then we
-                        * can say the other one is a rename.
+                        * are rename/copy entries using this one as
+                        * the source.  Then we can say one of them
+                        * is a rename and the rest are copies.
                         */
+                       p->status = 'D';
                        for (j = 0; j < q->nr; j++) {
                                pp = q->queue[j];
                                if (!strcmp(pp->one->path, p->one->path) &&
-                                   strcmp(pp->one->path, pp->two->path))
+                                   strcmp(pp->one->path, pp->two->path)) {
+                                       p->status = 'X';
                                        break;
+                               }
                        }
-                       if (j < q->nr)
-                               continue; /* has rename/copy */
-                       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 (strcmp(p->one->path, p->two->path)) {
                        /* See if there is somebody else anywhere that
                         * will keep the path (either modified or
@@ -719,7 +726,7 @@ static void diff_resolve_rename_copy(void)
                         * not a rename.  In addition, if there is
                         * some other rename or copy that comes later
                         * than us that uses the same source, we
-                        * cannot be a rename either.
+                        * have to be a copy, not a rename.
                         */
                        for (j = 0; j < q->nr; j++) {
                                pp = q->queue[j];
@@ -745,10 +752,9 @@ static void diff_resolve_rename_copy(void)
                }
                else if (memcmp(p->one->sha1, p->two->sha1, 20))
                        p->status = 'M';
-               else {
-                       /* we do not need this one */
-                       p->status = 0;
-               }
+               else
+                       /* this is a "no-change" entry */
+                       p->status = 'X';
        }
        diff_debug_queue("resolve-rename-copy done", q);
 }
@@ -767,8 +773,10 @@ void diff_flush(int diff_output_style, int resolve_rename_copy)
 
        for (i = 0; i < q->nr; i++) {
                struct diff_filepair *p = q->queue[i];
+               if (p->status == 'X')
+                       continue;
                if (p->status == 0)
-                       p->status = '?';
+                       die("internal error in diff-resolve-rename-copy");
                switch (diff_output_style) {
                case DIFF_FORMAT_PATCH:
                        diff_flush_patch(p);

diff --git a/diffcore.h b/diffcore.h
index 4610168..092eecc 100644 (file)
--- a/diffcore.h
+++ b/diffcore.h
@@ -45,6 +45,9 @@ struct diff_filepair {
 #define DIFF_PAIR_UNMERGED(p) \
        (!DIFF_FILE_VALID((p)->one) && !DIFF_FILE_VALID((p)->two))
 
+#define DIFF_PAIR_TYPE_CHANGED(p) \
+       ((S_IFMT & (p)->one->mode) != (S_IFMT & (p)->two->mode))
+
 extern int diff_unmodified_pair(struct diff_filepair *);
 
 struct diff_queue_struct {