Bug 1287126 - restore removal of space stuffing removed in changeset 99eb42a1fd3d. r=mkmelin

mail/test/mozmill/composition/test-drafts.js

@@ -236,6 +236,51 @@ function test_content_language_header() {
   press_delete(mc);
 }
 
+/**
+ * Tests space stuffing of plaintext message.
+ */
+function test_remove_space_stuffing_format_flowed() {
+  // Prepare for plaintext email.
+  let oldHtmlPref = Services.prefs.getBoolPref("mail.identity.default.compose_html");
+  Services.prefs.setBoolPref("mail.identity.default.compose_html", false);
+
+  let cwc = open_compose_new_mail();
+
+  setup_msg_contents(cwc, "test@example.invalid",
+                     "Testing space stuffing in plain text email",
+                     "NoSpace\n OneSpace\n  TwoSpaces");
+
+  cwc.window.SaveAsDraft();
+  utils.waitFor(() => !cwc.window.gSaveOperationInProgress && !cwc.window.gWindowLock,
+                "Saving of draft did not finish");
+  wait_for_window_focused(cwc.window);
+
+  close_compose_window(cwc);
+
+  be_in_folder(draftsFolder);
+
+  let draftMsg = select_click_row(0);
+
+  // Wait for the notification with the Edit button.
+  wait_for_notification_to_show(mc, kBoxId, "draftMsgContent");
+
+  plan_for_new_window("msgcompose");
+  mc.click(mc.eid(kBoxId, {tagName: "button", label: "Edit"}));
+  cwc = wait_for_compose_window();
+
+  let bodyText = cwc.e("content-frame").contentDocument
+                    .querySelector("body").innerHTML;
+
+  if (!bodyText.includes("NoSpace<br> OneSpace<br>  TwoSpaces")) {
+    assert_true(false, "Something went wrong with space stuffing");
+  }
+
+  // Clean up the created draft.
+  press_delete(mc);
+
+  Services.prefs.setBoolPref("mail.identity.default.compose_html", oldHtmlPref);
+}
+
 function teardownModule() {
   MailServices.accounts.localFoldersServer.rootFolder
               .propagateDelete(draftsFolder, true, null);

mailnews/mime/src/mimemsg.cpp

@@ -182,6 +182,12 @@ MimeMessage_parse_line (const char *aLine, int32_t aLength, MimeObject *obj)
       // line in mimeInlineTextPlainFlowedClass.
       if (mime_typep(kid, (MimeObjectClass *)&mimeInlineTextPlainFlowedClass))
       {
+        // Remove any stuffed space.
+        if (length > 0 && ' ' == *line)
+        {
+          line++;
+          length--;
+        }
         return kid->clazz->parse_line (line, length, kid);
       }
       else