[packages/rpm-build-tools] builder: rewrite code to checkout refs

[draenog]

commit 6217f40703a29f733a546091358749d912b639c4
Author: Kacper Kornet <draenog at pld-linux.org>
Date:   Thu Aug 23 14:12:43 2012 +0100

    builder: rewrite code to checkout refs
    
    git-checkout $CVSTAG can fail due to other reasons then non existing tag,
    i.e. when the merge is in progress. In previous version in such a remote
    tracking branch was tried to be check out, which resulted in error. It
    prevented user from checking if his merge commits builds correctly
    before commiting it.

 builder.sh | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)
---
diff --git a/builder.sh b/builder.sh
index e61f014..3284d47 100755
--- a/builder.sh
+++ b/builder.sh
@@ -785,6 +785,9 @@ Exit_error() {
 			remove_build_requires
 			echo >&2 "Error: problem with remote (${2})"
 			exit 13 ;;
+		"err_no_checkut" )
+			echo >&2 "Error: cannot checkout $2"
+			exit 14 ;;
 		"err_not_implemented" )
 			remove_build_requires
 			echo >&2 "Error: functionality not yet imlemented"
@@ -947,7 +950,14 @@ get_spec() {
 	fi
 
 	if [ -n "$CVSTAG" ]; then
-		git checkout "$CVSTAG" -- 2>/dev/null || git checkout -t "${REMOTE_PLD}/$CVSTAG" > /dev/null || exit
+		if git rev-parse --verify -q "$CVSTAG"; then
+			git checkout "$CVSTAG" --
+		elif git rev-parse --verify -q "refs/remotes/${REMOTE_PLD}/$CVSTAG"; then
+			git checkout -t "refs/remotes/${REMOTE_PLD}/$CVSTAG" > /dev/null
+		fi
+		if [ $(git rev-parse "$CVSTAG") != $(git rev-parse HEAD) ]; then
+			Exit_error "err_no_checkut" "$CVSTAG"
+		fi
 		git symbolic-ref -q HEAD > /dev/null &&
 			git merge '@{u}'
 		if [ -n "$CVSDATE" ]; then