commit 3ecdb3b8902b9b612bbe6a41b75086f16f35e97c
author Nicolas Lacasse <nlacasse@google.com> Wed Jan 13 17:33:36 2016 -0800
committer Nicolas Lacasse <nlacasse@google.com> Wed Jan 13 17:33:39 2016 -0800
tree 50175935c1205c43c1133f915f5904d85e4d59f9
parent e2548c46a191a43b5e3ad34df6a9b23df1fc6bbf

jiri: Use the latest update snapshot manifest when computing LocalProjects.

Previously, when computing LocalProjects with FastPath, we would read
the projects from the .jiri_manifest (or manifest specified on the
command line) and check to see if those projects exist on the local
filesystem.  If not, we fall back on the slow path of scanning the
entire filesystem for projects.

This behavior was incorrect.  In particular, since the .jiri_manifest
might have changed since the last update, we would end up scanning the
filesystem more often than necessary.

Now, we keep track of the latest update snapshot file with a symlink.
When computing LocalProjects, we read the manifest pointed to by that
symlink, which has a much higher probability of matching the projects on
the filesystem.  This will cause fewer filesystem scans.

MultiPart: 1/2
Change-Id: I526f30c8f4605edc02901dd8537e91baefc01807