abuild: warn if g++ is in makedepends. fix for dynamic deps

abuild.in

@@ -122,6 +122,8 @@ sanitycheck() {
 	[ -n "$makedepend" ] && die "APKBUILD contains 'makedepend'. It should be makedepends"
 
 	grep '^# Maintainer:' $APKBUILD >/dev/null || warning "No maintainer"
+
+	makedepends_has 'g++' && warning "g++ should not be in makedepends"
 	return 0
 }
 
@@ -403,8 +405,8 @@ trace_apk_deps() {
 		# first check if its provide by same apkbuild
 		for j in "$dir"/../*/.provides-so; do
 			grep -w "$i" "$j" >/dev/null || continue
-			found=${found%/.*}
-			found=${j##*/}
+			found=${j%/.provides-so}
+			found=${found##*/}
 			break
 		done
 		# check apk db if not provided by a subpackage