Merge debian/ instead of replace with unnecessary files.

container/bin/build_source

@@ -18,21 +18,6 @@ main() (
 		apt_source "$source"
 	fi
 
-	# if debian_source defined: remove debian folder from source and replace with debian folder from debian_source
-	if [ -n "$debian_source" ]; then
-		mkdir debian_src
-		cd debian_src
-		if [[ "$debian_source" = "git+"* ]]; then
-			git_source "${debian_source#git+}"
-		else
-			apt_source "$debian_source"
-		fi
-		rm -rf ../src/debian
-		mv src/debian ../src/
-		cd ..
-		rm -rf debian_src
-	fi
-
 	cd src
 	apply_patches /input
 
@@ -66,6 +51,10 @@ apt_source() (
 	debian=(*.debian.tar.*)
 	dsc=(*.dsc)
 	auto_decompress "$orig" > orig.tar
+	if [ -d /input/debian ]; then
+		echo "### Override debian folder with own content"
+		rsync -a /input/debian src/
+	fi
 	mkdir src
 	tar -C src -x --strip-components 1 < orig.tar
 	auto_decompress "$debian" | tar -C src -xv
@@ -75,6 +64,10 @@ apt_source() (
 git_source() (
 	IFS='#' read -r url ref <<< "$1"
 	git clone --bare --branch "$ref" --depth 1 "$url" src.git
+	if [ -d /input/debian ]; then
+		echo "### Replace debian folder with own content"
+		rsync -a /input/debian src/
+	fi
 	GIT_DIR=src.git git archive --prefix src/ "$ref" > orig.tar
 	rm -rf src.git
 	tar -x < orig.tar