Handle None lineno in get_source_context (getsentry#3925)

sentrivana · web-flow · commit 9ff100a981e1 · 2025-01-14T14:26:35.000+01:00
Be more defensive in `get_source_context`. The current check makes no sense as we first try to decrement `tb_lineno` and then check the result against `None`: ```python lineno = tb_lineno - 1 if lineno is not None and abs_path: ``` So it looks like this was an oversight/got broken at some point. Closes getsentry#3924
diff --git a/sentry_sdk/utils.py b/sentry_sdk/utils.py
@@ -571,7 +571,7 @@ def get_lines_from_file(
 
 def get_source_context(
     frame,  # type: FrameType
-    tb_lineno,  # type: int
+    tb_lineno,  # type: Optional[int]
     max_value_length=None,  # type: Optional[int]
 ):
     # type: (...) -> Tuple[List[Annotated[str]], Optional[Annotated[str]], List[Annotated[str]]]
@@ -587,11 +587,13 @@ def get_source_context(
         loader = frame.f_globals["__loader__"]
     except Exception:
         loader = None
-    lineno = tb_lineno - 1
-    if lineno is not None and abs_path:
+
+    if tb_lineno is not None and abs_path:
+        lineno = tb_lineno - 1
         return get_lines_from_file(
             abs_path, lineno, max_value_length, loader=loader, module=module
         )
+
     return [], None, []
 
 
