13403: Disable assertion rewriting for external modules - refactor

Author: Tusenka

src/_pytest/assertion/rewrite.py

@@ -218,12 +218,13 @@ def _early_rewrite_bailout(self, name: str, state: AssertionState) -> bool:
             if fnmatch_ex(pat, path):
                 return False
 
-        if not path.is_relative_to(state.root_path):
-            return True
 
         if self._is_marked_for_rewrite(name, state):
             return False
 
+        if not path.is_relative_to(state.root_path):
+            return True
+
         state.trace(f"early skip of rewriting module: {name}")
         return True
 
@@ -241,11 +242,9 @@ def _should_rewrite(self, name: str, fn: str, state: AssertionState) -> bool:
         # modules not passed explicitly on the command line are only
         # rewritten if they match the naming convention for test files
         fn_path = PurePath(fn)
-        if not fn_path.is_relative_to(state.root_path):
-            return False
 
         for pat in self.fnpats:
-            if fnmatch_ex(pat, fn_path):
+            if fnmatch_ex(pat, fn_path) and fn_path.is_relative_to(state.root_path):
                 state.trace(f"matched test file {fn!r}")
                 return True