Bug 1058565 - Correctly handle bad cache data. r=mshal

cache.py

@@ -4,7 +4,7 @@
 
 import shutil
 from cStringIO import StringIO
-from zipfile import ZipFile, ZIP_DEFLATED, BadZipfile
+from zipfile import ZipFile, ZIP_DEFLATED
 
 
 class CacheData(object):
@@ -22,10 +22,7 @@ class CacheData(object):
     def __init__(self, data=None):
         self._data = StringIO(data) if data else StringIO()
         self._obj = {}
-        try:
         self._zip = ZipFile(self._data, 'r' if data else 'w', ZIP_DEFLATED)
-        except BadZipfile:
-            self._zip = ZipFile(self._data, 'w', ZIP_DEFLATED)
 
     def __getitem__(self, key):
         if key not in self._obj:

server.py

@@ -254,6 +254,7 @@ def _run_command(job):
 
     outputs = {key: os.path.join(cwd, path) if cwd else path
         for key, path in parsed_args['output'].items()}
+    cache = None
     if preprocessed:
         # Compute the key corresponding to the preprocessor output, the command
         # line, and the compiler.
@@ -264,7 +265,11 @@ def _run_command(job):
             # Get cached data if there is.
             data = storage.get(cache_key)
             if data:
+                try:
                     cache = CacheData(data)
+                except:
+                    pass
+            if cache:
                 for key, path in outputs.items():
                     with open(path, 'wb') as obj:
                         obj.write(cache[key])
@@ -289,8 +294,6 @@ def _run_command(job):
                     cache[key] = f.read()
         except:
             cache = None
-    else:
-        cache = None
 
     if cache:
         status = 'miss'