branch: fix segfault when resolving an invalid HEAD

diff --git a/t/t6000lib.sh b/t/t6000lib.sh
index 01f796e9c827aff02c3161ac940626dd4d8edb9b..d40262159bce36e78dd56d931eaf1d007ef77da8 100755 (executable)
--- a/t/t6000lib.sh
+++ b/t/t6000lib.sh
@@ -51,7 +51,12 @@ as_author()
 
        export GIT_AUTHOR_EMAIL="$_author"
        "$@"
-        export GIT_AUTHOR_EMAIL="$_save"
+       if test -z "$_save"
+       then
+               unset GIT_AUTHOR_EMAIL
+       else
+               export GIT_AUTHOR_EMAIL="$_save"
+       fi
 }
 
 commit_date()
@@ -64,7 +69,9 @@ on_committer_date()
 {
     _date=$1
     shift 1
-    GIT_COMMITTER_DATE=$_date "$@"
+    export GIT_COMMITTER_DATE="$_date"
+    "$@"
+    unset GIT_COMMITTER_DATE
 }
 
 # Execute a command and suppress any error output.