Make SVN commit number an optional part of X-Mod-Pagespeed header.

chrome/browser/mod_pagespeed/mod_pagespeed_metrics.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/mod_pagespeed/mod_pagespeed_metrics.h"
 
 #include <stdio.h>
 
 #include <string>
 
@@ skipping 24 matching lines @@
   PAGESPEED_UNKNOWN_SERVER = 4,
   PAGESPEED_SERVER_MAXIMUM = 5
 };
 
 // Parse the PageSpeed version number and encodes it in buckets 2 through 99: if
 // it is in the format MAJOR.MINOR.BRANCH.POINT-COMMIT the bucket will be 2 + 2
 // * (max(BRANCH, 10) - 10) + (POINT > 1 ? 1 : 0); otherwise the bucket is
 // zero.
 int GetXModPagespeedBucketFromVersion(const std::string& version) {
   int unused_major, unused_minor, branch, point, unused_commit;
-  int num_parsed = sscanf(version.c_str(), "%d.%d.%d.%d-%d", &unused_major,
+  const char* version_string = version.c_str();
+  int num_parsed = sscanf(version_string, "%d.%d.%d.%d-%d", &unused_major,

[Charlie Harrison, 2016/10/31 20:29:00]

I wonder if you could do
sscanf(version_string, "%d.%d.%d.%d%c%d"), and if we match 6 successfully, just
double check that the character was a '-'. This way if we don't have the commit
we don't have to re-parse the version string.

                           &unused_minor, &branch, &point, &unused_commit);
+  if (num_parsed != 5) {
+    num_parsed = sscanf(version_string, "%d.%d.%d.%d", &unused_major,
+                        &unused_minor, &branch, &point);
+  }
   int output = 0;
-  if (num_parsed == 5) {
+  if (num_parsed == 4 || num_parsed == 5) {
     output = 2;
     if (branch > 10)
       output += 2 * (branch - 10);
     if (point > 1)
       output++;
     if (output < 2 || output > 99)
       output = 0;
   }
   return output;
 }
@@ skipping 75 matching lines @@
                                     PAGESPEED_UNKNOWN_SERVER,
                                     PAGESPEED_SERVER_MAXIMUM);
         }
       }
       break;
     }
   }
 }
 
 }  // namespace mod_pagespeed