From 8ccb0fda332ac46eaf4a821813c13f50b895a84f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ludovic=20Court=C3=A8s?= <ludo@gnu.org>
Date: Wed, 19 May 2010 21:27:01 +0000
Subject: [PATCH] fetchgit: Track all remote branches when `$rev' is non-empty.

svn path=/nixpkgs/trunk/; revision=21892
---
 pkgs/build-support/fetchgit/builder.sh | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/pkgs/build-support/fetchgit/builder.sh b/pkgs/build-support/fetchgit/builder.sh
index ba06aed90e1..794b690341e 100644
--- a/pkgs/build-support/fetchgit/builder.sh
+++ b/pkgs/build-support/fetchgit/builder.sh
@@ -5,7 +5,16 @@ header "exporting $url (rev $rev) into $out"
 git clone "$url" $out
 if test -n "$rev"; then
   cd $out
-  git checkout $rev
+
+  # Track all remote branches so that revisions like
+  # `t/foo@{2010-05-12}' are correctly resolved.  Failing to do that,
+  # Git bails out with an "invalid reference" error.
+  for branch in $(git branch -rl | grep -v ' origin/master$')
+  do
+    git branch --track "$(echo $branch | sed -es,origin/,,g)" "$branch"
+  done
+
+  git checkout "$rev" --
 fi
 
 if test -z "$leaveDotGit"; then