git-am: fix detection of absolute paths for windows

Add an is_absolute_path function to abstract out platform differences
in checking for an absolute or relative path.
Specifically fixes t4150-am on Windows.

[PT: updated following suggestion from j6t to support \* and //*]

Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Pat Thoyts <patthoyts@users.sourceforge.net>

1 files changed, 6 insertions, 6 deletions

diff --git a/git-am.sh b/git-am.sh
index e7f008c..9317b38 100755
--- a/git-am.sh
+++ b/git-am.sh
@@ -444,12 +444,12 @@ else
 				set x
 				first=
 			}
-			case "$arg" in
-			/*)
-				set "$@" "$arg" ;;
-			*)
-				set "$@" "$prefix$arg" ;;
-			esac
+			if is_absolute_path "$arg"
+			then
+				set "$@" "$arg"
+			else
+				set "$@" "$prefix$arg"
+			fi
 		done
 		shift
 	fi