pacman-mirror: allow 'push' even if only the databases changed

We will introduce the 'remove' command in the next commit. This command
will not require any new version of any package to be uploaded, yet it
still will need the databases to be uploaded.

Prepare the 'push' command to detect that situation.

The diff for this commit is best viewed with the `-w` option.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

Author: dscho

pacman-mirror.sh

@@ -213,53 +213,55 @@ push () {
 	to_upload="$(printf "%s\n%s\n%s\n" "$old_list" "$old_list" "$new_list" |
 		sort | uniq -u)"
 
-	test -n "$to_upload" || {
+	test -n "$to_upload" || test "x$old_list" != "x$new_list" || {
 		echo "Nothing to be done" >&2
 		return
 	}
 
-	to_upload_basenames="$(echo "$to_upload" |
-		sed 's/-[0-9].*//' |
-		sort | uniq)"
-
 	db_version="$(db_version)"
 	next_db_version="$(next_db_version "$db_version")"
 
-	# Verify that the packages exist already
-	for basename in $to_upload_basenames
-	do
-		case " $(echo "$old_list" | tr '\n' ' ')" in
-		*" $basename"-[0-9]*)
-			;;
-		*)
-			package_exists $basename ||
-			die "The package $basename does not yet exist... Add it at https://bintray.com/git-for-windows/pacman/new/package?pkgPath="
-			;;
-		esac
-	done
+	test -z "$to_upload" || {
+		to_upload_basenames="$(echo "$to_upload" |
+			sed 's/-[0-9].*//' |
+			sort | uniq)"
 
-	for name in $to_upload
-	do
-		basename=${name%%-[0-9]*}
-		version=${name#$basename-}
-		for arch in $architectures
+		# Verify that the packages exist already
+		for basename in $to_upload_basenames
 		do
-			case "$name" in
-			mingw-w64-*)
-				filename=$name-any.pkg.tar.xz
+			case " $(echo "$old_list" | tr '\n' ' ')" in
+			*" $basename"-[0-9]*)
 				;;
 			*)
-				filename=$name-$arch.pkg.tar.xz
+				package_exists $basename ||
+				die "The package $basename does not yet exist... Add it at https://bintray.com/git-for-windows/pacman/new/package?pkgPath="
 				;;
 			esac
-			(cd "$(arch_dir $arch)" &&
-			 if test -f $filename
-			 then
-				upload $basename $version $arch $filename
-			 fi) || exit
 		done
-		publish $basename $version
-	done
+
+		for name in $to_upload
+		do
+			basename=${name%%-[0-9]*}
+			version=${name#$basename-}
+			for arch in $architectures
+			do
+				case "$name" in
+				mingw-w64-*)
+					filename=$name-any.pkg.tar.xz
+					;;
+				*)
+					filename=$name-$arch.pkg.tar.xz
+					;;
+				esac
+				(cd "$(arch_dir $arch)" &&
+				 if test -f $filename
+				 then
+					upload $basename $version $arch $filename
+				 fi) || exit
+			done
+			publish $basename $version
+		done
+	}
 
 	delete_version package-database "$db_version"