Handle leading zeros in mod filenames

It's possible to put leading zeroes in the names of mod zip files which
cause the existing algorithm to find the mod zip from the mod version to
fail.  Fix by listing the mods directory and fixing the version numbers
for any of the mods with leading zeros in them.

packages/lib/factorio/export.js

@@ -357,6 +357,28 @@ async function exportData(server) {
 		throw new Error("No items got exported");
 	}
 
+	// Some mod authors put leading zeros into the versions of their zip files.
+	let splitter = /^(.*)_(\d+)\.(\d+)\.(\d+)\.zip?$/;
+	for (let entry of await fs.readdir(server.writePath("mods"))) {
+		let match = splitter.exec(entry);
+		if (!match) {
+			continue;
+		}
+
+		let modVersion = `${match[2]}.${match[3]}.${match[4]}`;
+		let normalizedVersion =
+			`${Number.parseInt(match[2], 10)}.${Number.parseInt(match[3], 10)}.${Number.parseInt(match[4], 10)}`
+		;
+
+		if (modVersion === normalizedVersion) {
+			continue;
+		}
+
+		if (modVersions.get(match[1]) === normalizedVersion) {
+			modVersions.set(match[1], modVersion);
+		}
+	}
+
 	let { iconSheet, itemData } = await exportItems(server, modVersions, items);
 	let locale = await exportLocale(server, modVersions, modOrder, "en");