1 files changed, 135 insertions, 0 deletions
diff --git a/browser/components/downloads/test/browser/browser_image_mimetype_issues.js b/browser/components/downloads/test/browser/browser_image_mimetype_issues.js
new file mode 100644
index 0000000000..b893a26d89
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+++ b/browser/components/downloads/test/browser/browser_image_mimetype_issues.js
@@ -0,0 +1,135 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+const TEST_ROOT = getRootDirectory(gTestPath).replace(
+  "chrome://mochitests/content",
+  "http://example.com"
+);
+
+var MockFilePicker = SpecialPowers.MockFilePicker;
+MockFilePicker.init(window);
+
+/*
+ * Popular websites implement image optimization as serving files with
+ * extension ".jpg" but content type "image/webp". If we save such images,
+ * we should actually save them with a .webp extension as that is what
+ * they are.
+ */
+
+/**
+ * Test the above with the "save image as" context menu.
+ */
+add_task(async function test_save_image_webp_with_jpeg_extension() {
+  await BrowserTestUtils.withNewTab(
+    `data:text/html,<img src="${TEST_ROOT}/not-really-a-jpeg.jpeg?convert=webp">`,
+    async browser => {
+      let menu = document.getElementById("contentAreaContextMenu");
+      let popupShown = BrowserTestUtils.waitForEvent(menu, "popupshown");
+      BrowserTestUtils.synthesizeMouse(
+        "img",
+        5,
+        5,
+        { type: "contextmenu", button: 2 },
+        browser
+      );
+      await popupShown;
+
+      await new Promise(resolve => {
+        MockFilePicker.showCallback = function (fp) {
+          ok(
+            fp.defaultString.endsWith("webp"),
+            `filepicker for image has "${fp.defaultString}", should end in webp`
+          );
+          setTimeout(resolve, 0);
+          return Ci.nsIFilePicker.returnCancel;
+        };
+        let menuitem = menu.querySelector("#context-saveimage");
+        menu.activateItem(menuitem);
+      });
+    }
+  );
+});
+
+/**
+ * Test with the "save link as" context menu.
+ */
+add_task(async function test_save_link_webp_with_jpeg_extension() {
+  await SpecialPowers.pushPrefEnv({
+    set: [
+      ["browser.download.always_ask_before_handling_new_types", false],
+      ["browser.download.useDownloadDir", false],
+    ],
+  });
+  await BrowserTestUtils.withNewTab(
+    `data:text/html,<a href="${TEST_ROOT}/not-really-a-jpeg.jpeg?convert=webp">Nice image</a>`,
+    async browser => {
+      let menu = document.getElementById("contentAreaContextMenu");
+      let popupShown = BrowserTestUtils.waitForEvent(menu, "popupshown");
+      BrowserTestUtils.synthesizeMouse(
+        "a[href]",
+        5,
+        5,
+        { type: "contextmenu", button: 2 },
+        browser
+      );
+      await popupShown;
+
+      await new Promise(resolve => {
+        MockFilePicker.showCallback = function (fp) {
+          ok(
+            fp.defaultString.endsWith("webp"),
+            `filepicker for link has "${fp.defaultString}", should end in webp`
+          );
+          setTimeout(resolve, 0);
+          return Ci.nsIFilePicker.returnCancel;
+        };
+        let menuitem = menu.querySelector("#context-savelink");
+        menu.activateItem(menuitem);
+      });
+    }
+  );
+});
+
+/**
+ * Test with the main "save page" command.
+ */
+add_task(async function test_save_page_on_image_document() {
+  await BrowserTestUtils.withNewTab(
+    `${TEST_ROOT}/not-really-a-jpeg.jpeg?convert=webp`,
+    async browser => {
+      await new Promise(resolve => {
+        MockFilePicker.showCallback = function (fp) {
+          ok(
+            fp.defaultString.endsWith("webp"),
+            `filepicker for "save page" has "${fp.defaultString}", should end in webp`
+          );
+          setTimeout(resolve, 0);
+          return Ci.nsIFilePicker.returnCancel;
+        };
+        document.getElementById("Browser:SavePage").doCommand();
+      });
+    }
+  );
+});
+
+/**
+ * Make sure that a valid JPEG image using the .JPG extension doesn't
+ * get it replaced with .jpeg.
+ */
+add_task(async function test_save_page_on_JPEG_image_document() {
+  await BrowserTestUtils.withNewTab(`${TEST_ROOT}/blank.JPG`, async browser => {
+    await new Promise(resolve => {
+      MockFilePicker.showCallback = function (fp) {
+        ok(
+          fp.defaultString.endsWith("JPG"),
+          `filepicker for "save page" has "${fp.defaultString}", should end in JPG`
+        );
+        setTimeout(resolve, 0);
+        return Ci.nsIFilePicker.returnCancel;
+      };
+      document.getElementById("Browser:SavePage").doCommand();
+    });
+  });
+});