extract: fix false warning about pattern never matching, fixes #4110

src/borg/patterns.py

@@ -131,8 +131,11 @@ class PatternMatcher:
         self.include_patterns = include_patterns
 
     def get_unmatched_include_patterns(self):
-        "Note that this only returns patterns added via *add_includepaths*."
-        return [p for p in self.include_patterns if p.match_count == 0]
+        """Note that this only returns patterns added via *add_includepaths* and it
+           won't return PathFullPattern patterns as we do not match_count for them.
+        """
+        return [p for p in self.include_patterns
+                if p.match_count == 0 and not isinstance(p, PathFullPattern)]
 
     def add_inclexcl(self, patterns):
         """Add list of patterns (of type CmdTuple) to internal list.