Merge branch 'jc/perl-cat-blob' into maint

diff --git a/builtin/apply.c b/builtin/apply.c
index 080ce2ea3e4d6290e5db5567c0bdd217725a36c4..06f5320b18bc5690ae944a722d19ec5496687228 100644 (file)
--- a/builtin/apply.c
+++ b/builtin/apply.c
@@ -3600,6 +3600,40 @@ static int get_current_sha1(const char *path, unsigned char *sha1)
        return 0;
 }
 
+static int preimage_sha1_in_gitlink_patch(struct patch *p, unsigned char sha1[20])
+{
+       /*
+        * A usable gitlink patch has only one fragment (hunk) that looks like:
+        * @@ -1 +1 @@
+        * -Subproject commit <old sha1>
+        * +Subproject commit <new sha1>
+        * or
+        * @@ -1 +0,0 @@
+        * -Subproject commit <old sha1>
+        * for a removal patch.
+        */
+       struct fragment *hunk = p->fragments;
+       static const char heading[] = "-Subproject commit ";
+       char *preimage;
+
+       if (/* does the patch have only one hunk? */
+           hunk && !hunk->next &&
+           /* is its preimage one line? */
+           hunk->oldpos == 1 && hunk->oldlines == 1 &&
+           /* does preimage begin with the heading? */
+           (preimage = memchr(hunk->patch, '\n', hunk->size)) != NULL &&
+           !prefixcmp(++preimage, heading) &&
+           /* does it record full SHA-1? */
+           !get_sha1_hex(preimage + sizeof(heading) - 1, sha1) &&
+           preimage[sizeof(heading) + 40 - 1] == '\n' &&
+           /* does the abbreviated name on the index line agree with it? */
+           !prefixcmp(preimage + sizeof(heading) - 1, p->old_sha1_prefix))
+               return 0; /* it all looks fine */
+
+       /* we may have full object name on the index line */
+       return get_sha1_hex(p->old_sha1_prefix, sha1);
+}
+
 /* Build an index that contains the just the files needed for a 3way merge */
 static void build_fake_ancestor(struct patch *list, const char *filename)
 {
@@ -3620,8 +3654,10 @@ static void build_fake_ancestor(struct patch *list, const char *filename)
                        continue;
 
                if (S_ISGITLINK(patch->old_mode)) {
-                       if (get_sha1_hex(patch->old_sha1_prefix, sha1))
-                               die("submoule change for %s without full index name",
+                       if (!preimage_sha1_in_gitlink_patch(patch, sha1))
+                               ; /* ok, the textual part looks sane */
+                       else
+                               die("sha1 information is lacking or useless for submoule %s",
                                    name);
                } else if (!get_sha1_blob(patch->old_sha1_prefix, sha1)) {
                        ; /* ok */