depcomp: avoid potential interferences from the environment

* lib/depcomp (gccflag, dashmflag): By explicitly initializing these
variables to the empty string by default.

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

diff --git a/lib/depcomp b/lib/depcomp
index 693fe04..e1f51f4 100755 (executable)
--- a/lib/depcomp
+++ b/lib/depcomp
@@ -74,6 +74,9 @@ tmpdepfile=${tmpdepfile-`echo "$depfile" | sed 's/\.\([^.]*\)$/.T\1/'`}
 
 rm -f "$tmpdepfile"
 
+# Avoid interferences from the environment.
+gccflag= dashmflag=
+
 # Some modes work just like other modes, but use different flags.  We
 # parameterize here, but still list the modes in the big case below,
 # to make depend.m4 easier to write.  Note that we *cannot* use a case