re-enabled quad-backticks, but allow triple-backticks as fences when searching for filenames #2879

aider/coders/base_coder.py

@@ -60,7 +60,7 @@ def wrap_fence(name):
 
 all_fences = [
     ("`" * 3, "`" * 3),
-    # ("`" * 4, "`" * 4), # LLMs ignore and revert to triple-backtick, causing #2879
+    ("`" * 4, "`" * 4),  # LLMs ignore and revert to triple-backtick, causing #2879
     wrap_fence("source"),
     wrap_fence("code"),
     wrap_fence("pre"),

aider/coders/editblock_coder.py

@@ -401,6 +401,9 @@ missing_filename_err = (
     " {fence[0]}"
 )
 
+# Always be willing to treat triple-backticks as a fence when searching for filenames
+triple_backticks = "`" * 3
+
 
 def strip_filename(filename, fence):
     filename = filename.strip()
@@ -409,7 +412,7 @@ def strip_filename(filename, fence):
         return
 
     start_fence = fence[0]
-    if filename.startswith(start_fence):
+    if filename.startswith(start_fence) or filename.startswith(triple_backticks):
         return
 
     filename = filename.rstrip(":")
@@ -546,7 +549,7 @@ def find_filename(lines, fence, valid_fnames):
             filenames.append(filename)
 
         # Only continue as long as we keep seeing fences
-        if not line.startswith(fence[0]):
+        if not line.startswith(fence[0]) and not line.startswith(triple_backticks):
             break
 
     if not filenames:

aider/main.py

@@ -991,6 +991,9 @@ def main(argv=None, input=None, output=None, force_git_root=None, return_coder=F
             analytics.event("exit", reason="Failed to read apply content")
             return
         coder.partial_response_content = content
+        # For testing #2879
+        # from aider.coders.base_coder import all_fences
+        # coder.fence = all_fences[1]
         coder.apply_updates()
         analytics.event("exit", reason="Applied updates")
         return