[3.8] bpo-25872: Fix KeyError in linecache when multithreaded (GH-18007) (GH-20092)
Backporting to 3.8 and adding a NEWS item (I should have added one to the master branch -- oh well).
diff --git a/Lib/linecache.py b/Lib/linecache.py
index 3afcce1..c87e180 100644
--- a/Lib/linecache.py
+++ b/Lib/linecache.py
@@ -73,10 +73,10 @@
try:
stat = os.stat(fullname)
except OSError:
- del cache[filename]
+ cache.pop(filename, None)
continue
if size != stat.st_size or mtime != stat.st_mtime:
- del cache[filename]
+ cache.pop(filename, None)
def updatecache(filename, module_globals=None):
@@ -86,7 +86,7 @@
if filename in cache:
if len(cache[filename]) != 1:
- del cache[filename]
+ cache.pop(filename, None)
if not filename or (filename.startswith('<') and filename.endswith('>')):
return []
diff --git a/Misc/NEWS.d/next/Library/2020-05-14-13-25-36.bpo-25872.5D5538.rst b/Misc/NEWS.d/next/Library/2020-05-14-13-25-36.bpo-25872.5D5538.rst
new file mode 100644
index 0000000..3fd8bac
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2020-05-14-13-25-36.bpo-25872.5D5538.rst
@@ -0,0 +1,2 @@
+:mod:`linecache` could crash with a :exc:`KeyError` when accessed from multiple threads.
+Fix by Michael Graczyk.