Merge branch 'jt/apply-reverse-twice'

gitster · gitster · commit c23cd78e8127 · 2020-11-02T13:17:43.000-08:00
"git apply -R" did not handle patches that touch the same path
twice correctly, which has been corrected.  This is most relevant
in a patch that changes a path from a regular file to a symbolic
link (and vice versa).

* jt/apply-reverse-twice:
  apply: when -R, also reverse list of sections
diff --git a/apply.c b/apply.c
@@ -4699,8 +4699,13 @@ static int apply_patch(struct apply_state *state,
 			reverse_patches(patch);
 		if (use_patch(state, patch)) {
 			patch_stats(state, patch);
-			*listp = patch;
-			listp = &patch->next;
+			if (!list || !state->apply_in_reverse) {
+				*listp = patch;
+				listp = &patch->next;
+			} else {
+				patch->next = list;
+				list = patch;
+			}
 
 			if ((patch->new_name &&
 			     ends_with_path_components(patch->new_name,
diff --git a/t/t4114-apply-typechange.sh b/t/t4114-apply-typechange.sh
@@ -88,6 +88,13 @@ test_expect_success 'symlink becomes file' '
 	'
 test_debug 'cat patch'
 
+test_expect_success 'symlink becomes file, in reverse' '
+	git checkout -f foo-symlinked-to-bar &&
+	git diff-tree -p HEAD foo-back-to-file > patch &&
+	git checkout foo-back-to-file &&
+	git apply -R --index < patch
+	'
+
 test_expect_success 'binary file becomes symlink' '
 	git checkout -f foo-becomes-binary &&
 	git diff-tree -p --binary HEAD foo-symlinked-to-bar > patch &&
diff --git a/t/t4127-apply-same-fn.sh b/t/t4127-apply-same-fn.sh
@@ -32,6 +32,10 @@ test_expect_success 'apply same filename with independent changes' '
 
 test_expect_success 'apply same filename with overlapping changes' '
 	git reset --hard &&
+
+	# Store same_fn so that we can check apply -R in next test
+	cp same_fn same_fn1 &&
+
 	modify "s/^d/z/" same_fn &&
 	git diff > patch0 &&
 	git add same_fn &&
@@ -43,6 +47,11 @@ test_expect_success 'apply same filename with overlapping changes' '
 	test_cmp same_fn same_fn2
 '
 
+test_expect_success 'apply same filename with overlapping changes, in reverse' '
+	git apply -R patch0 &&
+	test_cmp same_fn same_fn1
+'
+
 test_expect_success 'apply same new filename after rename' '
 	git reset --hard &&
 	git mv same_fn new_fn &&
