1 files changed, 32 insertions, 0 deletions
diff --git a/uriloader/exthandler/tests/unit/test_getMIMEInfo_unknown_mime_type.js b/uriloader/exthandler/tests/unit/test_getMIMEInfo_unknown_mime_type.js
new file mode 100644
index 0000000000..9beef9d9c5
--- /dev/null
+++ b/uriloader/exthandler/tests/unit/test_getMIMEInfo_unknown_mime_type.js
@@ -0,0 +1,32 @@
+/* Any copyright is dedicated to the Public Domain.
+http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+// Zip files can be opened by Windows explorer, so we should always be able to
+// determine a description and default handler for them. However, things can
+// get messy if they are sent to us with a mime type other than what Windows
+// considers the "right" mimetype (application/x-zip-compressed), like
+// application/zip, which is what most places (IANA, macOS, probably all linux
+// distros, Apache, etc.) think is the "right" mimetype.
+add_task(async function test_check_unknown_mime_type() {
+  const mimeService = Cc["@mozilla.org/mime;1"].getService(Ci.nsIMIMEService);
+  let zipType = mimeService.getTypeFromExtension("zip");
+  Assert.equal(zipType, "application/x-zip-compressed");
+  try {
+    let extension = mimeService.getPrimaryExtension("application/zip", "");
+    Assert.equal(
+      extension,
+      "zip",
+      "Expect our own info to provide an extension for zip files."
+    );
+  } catch (ex) {
+    Assert.ok(false, "We shouldn't throw when getting zip info.");
+  }
+  let found = {};
+  let mimeInfo = mimeService.getMIMEInfoFromOS("application/zip", "zip", found);
+  Assert.ok(
+    mimeInfo.hasDefaultHandler,
+    "Should have a default app for zip files"
+  );
+});