git-p4: auto-delete named temporary file

Avoid double-open exceptions on Windows platform when
calculating for lfs compressed size threshold
(git-p4.largeFileCompressedThreshold) comparisons.

Take new approach using the NamedTemporaryFile()
file-like object as input to the ZipFile() which
auto-deletes after implicit close leaving with scope.

Original code had double-open exception on Windows
platform because file still open from NamedTemporaryFile()
using generated filename instead of object.

Thanks to Andrey for patiently suggesting several
iterations on this change for avoiding exceptions!

Also print error details after resulting IOError to make
debugging cause of exception less mysterious when it has
nothing to do with "git version recent enough."

Signed-off-by: Philip.McGraw <Philip.McGraw@bentley.com>
Reviewed-by: Andrey Mazo <ahippo@yandex.com>
Acked-by: Luke Diamand <luke@diamand.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/git-p4.py b/git-p4.py
index 3991e7d1a7fc4d7206f8786a0d92ae5961ef0ef4..60c73b6a374ccce59ef922c26704f8e5e244b7ef 100755 (executable)
--- a/git-p4.py
+++ b/git-p4.py
@@ -1160,13 +1160,11 @@ class LargeFileSystem(object):
             if contentsSize <= gitConfigInt('git-p4.largeFileCompressedThreshold'):
                 return False
             contentTempFile = self.generateTempFile(contents)
-            compressedContentFile = tempfile.NamedTemporaryFile(prefix='git-p4-large-file', delete=False)
-            zf = zipfile.ZipFile(compressedContentFile.name, mode='w')
-            zf.write(contentTempFile, compress_type=zipfile.ZIP_DEFLATED)
-            zf.close()
-            compressedContentsSize = zf.infolist()[0].compress_size
+            compressedContentFile = tempfile.NamedTemporaryFile(prefix='git-p4-large-file', delete=True)
+            with zipfile.ZipFile(compressedContentFile, mode='w') as zf:
+                zf.write(contentTempFile, compress_type=zipfile.ZIP_DEFLATED)
+                compressedContentsSize = zf.infolist()[0].compress_size
             os.remove(contentTempFile)
-            os.remove(compressedContentFile.name)
             if compressedContentsSize > gitConfigInt('git-p4.largeFileCompressedThreshold'):
                 return True
         return False
@@ -3525,8 +3523,9 @@ class P4Sync(Command, P4UserMap):
         self.updateOptionDict(details)
         try:
             self.commit(details, self.extractFilesFromCommit(details), self.branch)
-        except IOError:
+        except IOError as err:
             print("IO error with git fast-import. Is your git version recent enough?")
+            print("IO error details: {}".format(err))
             print(self.gitError.read())
 
     def openStreams(self):