support for resuming partial downloads. check md5 in separate step

abuild

@@ -23,7 +23,7 @@ pkgrel=0
 SRCDEST=${SRCDEST:-$startdir}
 PKGDEST=${PKGDEST:-$startdir}
 
-default_cmds="checkdeps clean fetch unpack rootpkg"
+default_cmds="checkdeps clean fetch checkmd5 unpack rootpkg"
 all_cmds="checksum fetch unpack rootpkg build package cleancache clean srcpkg"
 
 # functions
@@ -56,20 +56,26 @@ checkdeps() {
 }
 
 checkmd5() {
-	( cd "$SRCDEST" && echo "$md5sums" | awk '$2 == "'$1'" { print $0 } ' \
-		| md5sum -c )
+	if [ -z "$md5sums" ]; then
+		die "Use 'abuild checksum >>$APKBUILD' to generate a checksum"
+	fi
+	cd "$srcdir" && echo "$md5sums" | md5sum -c 
 }
 
 uri_fetch() {
 	local uri="$1"
 	local d="${s##*/}"	# $(basename $s)
-	local q
-	[ -n "$quiet" ] && q="-q"
+	local opts
+	[ -n "$quiet" ] && opts="-q"
+	[ -f "$SRCDEST/$d" ] && return 0
+
 	mkdir -p "$SRCDEST"
-	if ! [ -f "$SRCDEST/$d" ] || ! checkmd5 "$d" 2>/dev/null; then
-		rm -f "$SRCDEST/$d"
-		wget $q -c -P "$SRCDEST" "$uri" && checkmd5 "$d" 
+	if [ -f "$SRCDEST/$d.part" ]; then
+		msg "Partial download found. Trying to resume"
+		opts="$opts -c"
 	fi
+	wget $opts -O "$SRCDEST/$d.part" "$uri" \
+		&& mv "$SRCDEST/$d.part" "$SRCDEST/$d"
 }
 
 fetch() {
@@ -80,10 +86,6 @@ fetch() {
 			http://*|ftp://*)
 				uri_fetch "$s" || return 1
 				;;
-			*)
-				[ -n "$genchecksum" ] && continue
-				checkmd5 "${s##*/}" || return 1
-				;;
 		esac
 		ln -sf "$SRCDEST/${s##*/}" "$srcdir"/
 	done
@@ -92,7 +94,6 @@ fetch() {
 # unpack the sources
 unpack() {
 	local u
-	[ -z "$md5sums" ] && die "Use 'abuild checksum >>$APKBUILD' to generate a checksum"
 	mkdir -p "$srcdir"
 	for u in $source; do
 		local s="$SRCDEST/${u##*/}"	# $(basename $s)