Fallback to simple file copy if rename failed

src/Site/SiteStorage.py

@@ -175,7 +175,7 @@ class SiteStorage:
                 err = None
                 break
             except Exception, err:
-                self.log.error("%s rename error: %s" % (inner_path_before, err))
+                self.log.error("%s rename error: %s (retry #%s)" % (inner_path_before, err, retry))
                 time.sleep(0.1 + retry)
         if err:
             raise err

src/Ui/UiWebsocket.py

@@ -3,7 +3,7 @@ import time
 import sys
 import hashlib
 import os
-import re
+import shutil
 
 import gevent
 
@@ -383,8 +383,14 @@ class UiWebsocket(object):
             import base64
             content = base64.b64decode(content_base64)
             # Save old file to generate patch later
-            if self.site.storage.isFile(inner_path) and not self.site.storage.isFile(inner_path+"-old"):
+            if inner_path.endswith(".json") and self.site.storage.isFile(inner_path) and not self.site.storage.isFile(inner_path + "-old"):
+                try:
                     self.site.storage.rename(inner_path, inner_path + "-old")
+                except Exception:
+                    # Rename failed, fall back to standard file write
+                    f_old = self.site.storage.open(inner_path, "rb")
+                    f_new = self.site.storage.open(inner_path + "-old", "wb")
+                    shutil.copyfileobj(f_old, f_new)
 
             self.site.storage.write(inner_path, content)
         except Exception, err: