Bug 1964507 - Only offer "Add Search Engine" for GET forms. r=search-reviewers,Standard8

Differential Revision: https://phabricator.services.mozilla.com/D250020

browser/components/search/test/browser/browser_addSearchEngineFromForm.js

@@ -27,18 +27,6 @@ const TESTS = [
     submission: "kitten",
     expected: "https://example.org/search?q=kitten&utf8%E2%9C%93=%E2%9C%93",
   },
-  {
-    action: "/search",
-    method: "POST",
-    charset: "UTF-8",
-    fields: [
-      { name: "q", value: "Some initial value", main: true },
-      { name: "utf8✓", value: "✓", hidden: true },
-    ],
-    submission: "kitten",
-    expected: "https://example.org/search",
-    expectedPost: "q=kitten&utf8%E2%9C%93=%E2%9C%93",
-  },
   {
     action: "/search",
     method: "GET",
@@ -51,18 +39,6 @@ const TESTS = [
     submission: "caff\u00E8+",
     expected: "https://example.org/search?q=caff%E8%2B&cb=true",
   },
-  {
-    action: "/search",
-    method: "POST",
-    charset: "windows-1252",
-    fields: [
-      { name: "q", main: true },
-      { name: "foo", value: "bar" },
-    ],
-    submission: "caff\u00E8+",
-    expected: "https://example.org/search",
-    expectedPost: "q=caff%E8%2B&foo=bar",
-  },
 ];
 
 const URL_UTF_8 =
@@ -249,6 +225,10 @@ add_task(async function testSearchFieldDetection() {
   Assert.equal(isSearchField, false, "Method=dialog means no search field");
 
   form.method = "POST";
+  isSearchField = SpellCheckHelper.isTargetASearchEngineField(input, window);
+  Assert.equal(isSearchField, false, "Method=post means no search field");
+
+  form.method = "GET";
 
   delete input.removeAttribute("name");
   isSearchField = SpellCheckHelper.isTargetASearchEngineField(input, window);

toolkit/modules/InlineSpellChecker.sys.mjs

@@ -500,8 +500,10 @@ export var SpellCheckHelper = {
     return (
       // Forms without an explicit action often don't work, see Bug 1960237.
       form.hasAttribute("action") &&
-      // The only other method is dialog.
-      (method == "GET" || method == "POST") &&
+      // The other methods are post and dialog.
+      // Post forms are rarely search forms, see discussion in Bug 1964507.
+      // Dialog forms are not supported for obvious reasons.
+      method == "GET" &&
       // SearchEngine objects currently only support urlencoded requests.
       form.enctype == "application/x-www-form-urlencoded" &&
       // Don't allow forms with file inputs.