depcomp: avoid an extra fork when possible

* lib/depcomp (set_dir_from): Here.

Signed-off-by: Stefano Lattarini <stefano.lattarini@gmail.com>

diff --git a/lib/depcomp b/lib/depcomp
index 1707586..23a9fcb 100755 (executable)
--- a/lib/depcomp
+++ b/lib/depcomp
@@ -61,8 +61,10 @@ esac
 # be either empty or ending with a '/' character.  This is deliberate.
 set_dir_from ()
 {
-  dir=`echo "$1" | sed -e 's|/[^/]*$|/|'`
-  test "x$dir" = "x$1" && dir=
+  case $1 in
+    */*) dir=`echo "$1" | sed -e 's|/[^/]*$|/|'`;;
+      *) dir=;;
+  esac
 }
 
 # Get the suffix-stripped basename of the given path, and save it the