Protect CROSS_PATH against spurious addition of linebreaks from isolated dashes

fix for #3989

Author: martin-frbg

c_check

@@ -35,9 +35,12 @@ if [ "`dirname \"$compiler_name\"`" != '.' ]; then
     cross_suffix="$cross_suffix`dirname \"$compiler_name\"`/"
 fi
 
-bn=`basename $compiler_name`
+bn=`basename \"$compiler_name\"`
+
 case "$bn" in
-    *-*) cross_suffix="$cross_suffix${bn%-*}-"
+    *-*) if [ "$bn" != '-']; then
+           cross_suffix="$cross_suffix${bn%-*}-"
+         fi
 esac
 
 compiler=""