[libfuzzer] Turn warnings from zipfile into errors while archiving seed corpus.

testing/libfuzzer/archive_corpus.py

Index: testing/libfuzzer/archive_corpus.py
diff --git a/testing/libfuzzer/archive_corpus.py b/testing/libfuzzer/archive_corpus.py
index 7e39bb54e449812ecf275775b07a9454f3e94923..71c132b5b215f5a666578cc757eeb2d52d8ee367 100755
--- a/testing/libfuzzer/archive_corpus.py
+++ b/testing/libfuzzer/archive_corpus.py
@@ -13,6 +13,7 @@ from __future__ import print_function
 import argparse
 import os
 import sys
+import warnings
 import zipfile
 
 
@@ -31,8 +32,13 @@ def main():
       corpus_files.append(full_filename)
 
   with zipfile.ZipFile(args.output, 'w') as z:
-    for corpus_file in corpus_files:
-        z.write(corpus_file, os.path.basename(corpus_file))
+    # Turn warnings into errors to interrupt the build: crbug.com/653920.
+    with warnings.catch_warnings():
+      warnings.simplefilter("error")
+      for i, corpus_file in enumerate(corpus_files):
+        # To avoid duplication of filenames inside the archive, use numbers.
+        arcname = '%016d' % i

[mmoroz, 2016/11/29 13:53:41]

I thought to use subdirectory_name + '_' + os.path.basename(corpus_file), but
names of corpus files are not important, so that complication wouldn't make
sense.

+        z.write(corpus_file, arcname)
 
 
 if __name__ == '__main__':