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

chrome/browser/mod_pagespeed/mod_pagespeed_metrics.cc

Index: chrome/browser/mod_pagespeed/mod_pagespeed_metrics.cc
diff --git a/chrome/browser/mod_pagespeed/mod_pagespeed_metrics.cc b/chrome/browser/mod_pagespeed/mod_pagespeed_metrics.cc
index f17c005359d615f9f2bbeb203a59cdd71f2c2f13..89c7a87c490c1f73917ad5a2368b55f04dfc072d 100644
--- a/chrome/browser/mod_pagespeed/mod_pagespeed_metrics.cc
+++ b/chrome/browser/mod_pagespeed/mod_pagespeed_metrics.cc
@@ -42,10 +42,15 @@ enum PagespeedHeaderServerType {
 // 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);