Merge branch 'jc/fake-ancestor-with-non-blobs' into maint

Rebasing the history of superproject with change in the submodule
has been broken since v1.7.12.

* jc/fake-ancestor-with-non-blobs:
  apply: diagnose incomplete submodule object name better
  apply: simplify build_fake_ancestor()
  git-am: record full index line in the patch used while rebasing

builtin/apply.c

@@ -3609,7 +3609,6 @@ static void build_fake_ancestor(struct patch *list, const char *filename)
 	 * worth showing the new sha1 prefix, but until then...
 	 */
 	for (patch = list; patch; patch = patch->next) {
-		const unsigned char *sha1_ptr;
 		unsigned char sha1[20];
 		struct cache_entry *ce;
 		const char *name;
@@ -3617,20 +3616,23 @@ static void build_fake_ancestor(struct patch *list, const char *filename)
 		name = patch->old_name ? patch->old_name : patch->new_name;
 		if (0 < patch->is_new)
 			continue;
-		else if (get_sha1_blob(patch->old_sha1_prefix, sha1))
-			/* git diff has no index line for mode/type changes */
-			if (!patch->lines_added && !patch->lines_deleted) {
-				if (get_current_sha1(patch->old_name, sha1))
-					die("mode change for %s, which is not "
-						"in current HEAD", name);
-				sha1_ptr = sha1;
-			} else
-				die("sha1 information is lacking or useless "
-					"(%s).", name);
-		else
-			sha1_ptr = sha1;
 
-		ce = make_cache_entry(patch->old_mode, sha1_ptr, name, 0, 0);
+		if (S_ISGITLINK(patch->old_mode)) {
+			if (get_sha1_hex(patch->old_sha1_prefix, sha1))
+				die("submoule change for %s without full index name",
+				    name);
+		} else if (!get_sha1_blob(patch->old_sha1_prefix, sha1)) {
+			; /* ok */
+		} else if (!patch->lines_added && !patch->lines_deleted) {
+			/* mode-only change: update the current */
+			if (get_current_sha1(patch->old_name, sha1))
+				die("mode change for %s, which is not "
+				    "in current HEAD", name);
+		} else
+			die("sha1 information is lacking or useless "
+			    "(%s).", name);
+
+		ce = make_cache_entry(patch->old_mode, sha1, name, 0, 0);
 		if (!ce)
 			die(_("make_cache_entry failed for path '%s'"), name);
 		if (add_index_entry(&result, ce, ADD_CACHE_OK_TO_ADD))

git-am.sh

@@ -664,7 +664,7 @@ do
 			sed -e '1,/^$/d' >"$dotest/msg-clean"
 			echo "$commit" >"$dotest/original-commit"
 			get_author_ident_from_commit "$commit" >"$dotest/author-script"
-			git diff-tree --root --binary "$commit" >"$dotest/patch"
+			git diff-tree --root --binary --full-index "$commit" >"$dotest/patch"
 		else
 			git mailinfo $keep $no_inbody_headers $scissors $utf8 "$dotest/msg" "$dotest/patch" \
 				<"$dotest/$msgnum" >"$dotest/info" ||

t/t7402-submodule-rebase.sh

@@ -3,7 +3,7 @@
 # Copyright (c) 2008 Johannes Schindelin
 #
 
-test_description='Test rebasing and stashing with dirty submodules'
+test_description='Test rebasing, stashing, etc. with submodules'
 
 . ./test-lib.sh
 
@@ -20,7 +20,8 @@ test_expect_success setup '
 	echo second line >> file &&
 	(cd submodule && git pull) &&
 	test_tick &&
-	git commit -m file-and-submodule -a
+	git commit -m file-and-submodule -a &&
+	git branch added-submodule
 
 '
 
@@ -89,4 +90,29 @@ test_expect_success 'stash with a dirty submodule' '
 
 '
 
+test_expect_success 'rebasing submodule that should conflict' '
+	git reset --hard &&
+	git checkout added-submodule &&
+	git add submodule &&
+	test_tick &&
+	git commit -m third &&
+	(
+		cd submodule &&
+		git commit --allow-empty -m extra
+	) &&
+	git add submodule &&
+	test_tick &&
+	git commit -m fourth &&
+
+	test_must_fail git rebase --onto HEAD^^ HEAD^ HEAD^0 &&
+	git ls-files -s submodule >actual &&
+	(
+		cd submodule &&
+		echo "160000 $(git rev-parse HEAD^) 1	submodule" &&
+		echo "160000 $(git rev-parse HEAD^^) 2	submodule" &&
+		echo "160000 $(git rev-parse HEAD) 3	submodule"
+	) >expect &&
+	test_cmp expect actual
+'
+
 test_done