contrib: Change 'remote' for personal branches and add branch creation script

Whilst trying to convert the add vendor branch script to work with
personal branches I encountered a minor issue where git would report
ambiguous refs when checking out the new branch.

It turns out that this is because git considers <me>/<topic> to be
ambiguous if both

  refs/heads/<me>/<topic>

and

  refs/remotes/<me>/<topic>

exist in the list of known branches.

Having thought about this a bit, I think the best solution is to adopt
something more like the vendors space and call the remote users/<me>
(this also works better if you want to set up remotes to track other
users branches as well).

So this patch has two parts.

1) It updates gcc-git-customization.sh to set up the new 'remote' and
converts any existing remote and branches tracking that to the new
format
2) It adds a new script to set up a personal branch on the gcc git repository.

	* gcc-git-customization.sh: Use users/<pfx> for the personal remote
	rather than just <pfx>.  Convert any existing personal branches to the
	new remote.
	* git-add-user-branch.sh: New file.

1 files changed, 46 insertions, 0 deletions

diff --git a/contrib/git-add-user-branch.sh b/contrib/git-add-user-branch.sh
new file mode 100755
index 00000000000..e014f7518fb
--- /dev/null
+++ b/contrib/git-add-user-branch.sh
@@ -0,0 +1,46 @@
+#! /bin/sh -e
+
+# Create a new upstream user branch.
+
+# Usage:
+#  contrib/git-add-user-branch.sh [<personal-prefix>/]<branch-name> <base>
+
+usage ()
+{
+    echo "Usage:"
+    echo "  $0 [<personal-prefix>/]<branch-name> <start-point>"
+    echo
+    echo "personal space must already have been set up using"
+    echo "contrib/gcc-git-customization.sh"
+    exit 1
+}
+
+if [ $# != 2 ]
+then
+    usage
+fi
+
+userpfx=$(git config --get "gcc-config.userpfx")
+user=$(git config --get "gcc-config.user")
+
+if [ -z "$userpfx" -o -z "$user" ]
+then
+    usage
+fi
+
+branch=$(echo "$1" | sed -r "s:(${userpfx}/)?(.*)$:\2:")
+start=$2
+
+# Sanity check the new branch argument.  If there is no '/', then the
+# vendor will be the same as the entire first argument.
+if [ -z "$branch" ]
+then
+    usage
+fi
+
+git push users/${userpfx} ${start}:refs/users/${user}/heads/${branch}
+git fetch -q users/${userpfx}
+git branch ${userpfx}/${branch} remotes/users/${userpfx}/${branch}
+echo "You are now ready to check out ${userpfx}/${branch}"
+echo "To push the branch upstream use:"
+echo "  git push users/${userpfx} ${userpfx}/${branch}"