Make path reversable in map_editor()

1 files changed, 13 insertions, 11 deletions

diff --git a/path.c b/path.c
index 450ea91..f604ec1 100644
--- a/path.c
+++ b/path.c
@@ -337,14 +337,19 @@ void path_free(Path path, size_t height) {
 }
 
 void path_reverse(Path *path, size_t width, size_t height, Position *start, Position *end) {
-    Path new_path = path_new(width, height);
-    if (new_path == NULL) error("Failed to allocate path\n");
-
-    Position cur = *end;
-    while (cur.x != start->x || cur.y != start->y) {
-        Position parent = (*path)[cur.y][cur.x];
-        new_path[parent.y][parent.x] = cur;
-        cur = parent;
+    if (*path != NULL) {
+        Path new_path = path_new(width, height);
+        if (new_path == NULL) error("Failed to allocate path\n");
+
+        Position cur = *end;
+        while (cur.x != start->x || cur.y != start->y) {
+            Position parent = (*path)[cur.y][cur.x];
+            new_path[parent.y][parent.x] = cur;
+            cur = parent;
+        }
+
+        path_free(*path, height);
+        *path = new_path;
     }
 
     /* Switch start and end around */
@@ -356,9 +361,6 @@ void path_reverse(Path *path, size_t width, size_t height, Position *start, Posi
     end->y   ^= start->y;
     start->y ^= end->y;
 
-    path_free(*path, height);
-    *path = new_path;
-
     return;
 }