Workspaces created from AU tags are now identified

Change-Id: Ic165faaa2593584246e1cc35c2c33352b6c84e24

treeid.sh

 #!/bin/bash
 #
-# Attempt to identify the Android tree in use.  On success one or more
+# Attempt to identify the tree in use.  On success one or more
 # tree identifiers are output to stdout.
 #
 # Copyright (c) 2012-2015, The Linux Foundation. All rights reserved.
@@ -36,20 +36,26 @@ if [[ ! ( -f build/envsetup.sh ) ]]; then
    exit 1
 fi
 
-TREEID=
 if [[ -f .repo/manifest.xml ]] ; then
-   # Tokenize <default revision="x_y_z"/> by '_'
-   TOKENS=$(repo info -l .repo/manifest 2>/dev/null | sed -e '/merge/!d ; s/^.*branch:// ; s/.*\///; s/.*b2g_//g;')
-
-   MANIFEST_ID=
-   for T in $TOKENS; do
-      if [ -z $MANIFEST_ID ]; then
-        MANIFEST_ID=$T
-      else
-        MANIFEST_ID=${MANIFEST_ID}_$T
-      fi
-      TREEID="$MANIFEST_ID $TREEID"
-   done
+   mergeBranch=$(repo info -l .repo/manifest 2>/dev/null | sed -ne 's/^Manifest merge branch: \(.*\)$/\1/p')
+
+   # Drop 'ref/tags/' if present
+   mergeBranch=$(basename $mergeBranch)
+
+   # Check for an AU tag and extract the corresponding branch name
+   mergeBranch=${mergeBranch#AU_LINUX_GECKO_}
+   mergeBranch=${mergeBranch%.[0-9][0-9].[0-9][0-9].[0-9][0-9].[0-9][0-9][0-9].[0-9][0-9][0-9]}
+
+   # Old-style branch names are lowercase
+   if [[ $mergeBranch =~ ^B2G_ ]]; then
+     mergeBranch=${mergeBranch,,}
+   fi
+
+   # Drop b2g_ prefix from old-style branch names
+   mergeBranch=${mergeBranch#b2g_}
+
+   echo $mergeBranch all
+else
+   echo all
 fi
 
-echo $TREEID all