[iOS] Fix error page detection in helper

This CL fixes the ErrorPageHelper detection of the original URL in an
error page URL.
It used to not used the same keyword as the creation method.

Bug: 991608
Change-Id: Ib826b879e539b5d21ccde2d6e92dbba7adccff49
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2027334Reviewed-by: Eugene But <eugenebut@chromium.org>
Commit-Queue: Gauthier Ambard <gambard@chromium.org>
Auto-Submit: Gauthier Ambard <gambard@chromium.org>
Cr-Commit-Position: refs/heads/master@{#737837}

ios/web/navigation/error_page_helper.mm

@@ -16,6 +16,8 @@
 
 namespace {
 
+const char kOriginalUrlKey[] = "url";
+
 // Escapes HTML characters in |text|.
 NSString* EscapeHTMLCharacters(NSString* text) {
   return base::SysUTF8ToNSString(
@@ -76,9 +78,9 @@ NSString* InjectedErrorPageFilePath() {
 
 - (NSURL*)errorPageFileURL {
   if (!_errorPageFileURL) {
-    NSURLQueryItem* itemURL =
-        [NSURLQueryItem queryItemWithName:@"url"
-                                    value:self.failedNavigationURLString];
+    NSURLQueryItem* itemURL = [NSURLQueryItem
+        queryItemWithName:base::SysUTF8ToNSString(kOriginalUrlKey)
+                    value:self.failedNavigationURLString];
     NSURLQueryItem* itemError =
         [NSURLQueryItem queryItemWithName:@"error"
                                     value:_error.localizedDescription];
@@ -137,10 +139,9 @@ NSString* InjectedErrorPageFilePath() {
 
   if (URL.SchemeIsFile() &&
       URL.path() == base::SysNSStringToUTF8(LoadedErrorPageFilePath())) {
-    for (net::QueryIterator it(URL); !it.IsAtEnd(); it.Advance()) {
-      if (it.GetKey() == "file") {
-        return GURL(it.GetValue());
-      }
+    std::string value;
+    if (net::GetValueForKeyInQuery(URL, kOriginalUrlKey, &value)) {
+      return GURL(value);
     }
   }
 
@@ -157,7 +158,7 @@ NSString* InjectedErrorPageFilePath() {
                                               resolvingAgainstBaseURL:NO];
   NSURL* failedNavigationURL = nil;
   for (NSURLQueryItem* item in URLComponents.queryItems) {
-    if ([item.name isEqualToString:@"url"]) {
+    if ([item.name isEqualToString:base::SysUTF8ToNSString(kOriginalUrlKey)]) {
       failedNavigationURL = [NSURL URLWithString:item.value];
       break;
     }

ios/web/navigation/error_page_helper_unittest.mm

@@ -5,6 +5,7 @@
 #import "ios/web/navigation/error_page_helper.h"
 
 #include "base/strings/sys_string_conversions.h"
+#import "net/base/mac/url_conversions.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #import "testing/gtest_mac.h"
 #include "testing/platform_test.h"
@@ -28,6 +29,48 @@ TEST_F(ErrorPageHelperTest, FailedNavigationURL) {
   EXPECT_NSEQ(url, helper.failedNavigationURL);
 }
 
+// Tests that the original URL is correctly extracted from the file error URL
+// created by the helper.
+TEST_F(ErrorPageHelperTest, ExtractOriginalURLFromErrorPageURL) {
+  NSString* url_string = @"https://test-error-page.com";
+  NSError* error = [NSError
+      errorWithDomain:NSURLErrorDomain
+                 code:NSURLErrorBadURL
+             userInfo:@{NSURLErrorFailingURLStringErrorKey : url_string}];
+  ErrorPageHelper* helper = [[ErrorPageHelper alloc] initWithError:error];
+  GURL result_original_url = [ErrorPageHelper
+      failedNavigationURLFromErrorPageFileURL:net::GURLWithNSURL(
+                                                  helper.errorPageFileURL)];
+  EXPECT_EQ(GURL(base::SysNSStringToUTF8(url_string)), result_original_url);
+}
+
+// Tests that the error page is correctly identified as error page.
+TEST_F(ErrorPageHelperTest, IsErrorPageFileURL) {
+  NSString* url_string = @"https://test-error-page.com";
+  NSError* error = [NSError
+      errorWithDomain:NSURLErrorDomain
+                 code:NSURLErrorBadURL
+             userInfo:@{NSURLErrorFailingURLStringErrorKey : url_string}];
+  ErrorPageHelper* helper = [[ErrorPageHelper alloc] initWithError:error];
+  EXPECT_TRUE([helper
+      isErrorPageFileURLForFailedNavigationURL:helper.errorPageFileURL]);
+}
+
+// Tests that a normal URL isn't identified as error page.
+TEST_F(ErrorPageHelperTest, IsErrorPageFileURLWrong) {
+  NSString* url_string = @"file://test-error-page.com";
+  NSError* error =
+      [NSError errorWithDomain:NSURLErrorDomain
+                          code:NSURLErrorBadURL
+                      userInfo:@{
+                        NSURLErrorFailingURLStringErrorKey : @"http://fake.com"
+                      }];
+  ErrorPageHelper* helper = [[ErrorPageHelper alloc] initWithError:error];
+  EXPECT_FALSE([helper
+      isErrorPageFileURLForFailedNavigationURL:[NSURL
+                                                   URLWithString:url_string]]);
+}
+
 // Tests that the failed navigation URL is correctly extracted from the page
 // URL.
 TEST_F(ErrorPageHelperTest, FailedNavigationURLFromErrorPageFileURLCorrect) {
@@ -37,14 +80,14 @@ TEST_F(ErrorPageHelperTest, FailedNavigationURLFromErrorPageFileURLCorrect) {
                ofType:@"html"]);
 
   std::string url_string = "file://" + path +
-                           "?url=http://not-that-url.com&file=" + expected_url +
+                           "?file=http://not-that-url.com&url=" + expected_url +
                            "&garbage=http://still-not-that-one.com";
   GURL result_url = [ErrorPageHelper
       failedNavigationURLFromErrorPageFileURL:GURL(url_string)];
   EXPECT_EQ(GURL(expected_url), result_url);
 }
 
-// Tests that the extract failed navigation URL is empty if the |file| query
+// Tests that the extract failed navigation URL is empty if the |url| query
 // isn't present in the page URL.
 TEST_F(ErrorPageHelperTest, FailedNavigationURLFromErrorPageFileURLNoQuery) {
   std::string expected_url = "http://expected-url.com";
@@ -52,7 +95,7 @@ TEST_F(ErrorPageHelperTest, FailedNavigationURLFromErrorPageFileURLNoQuery) {
       pathForResource:@"error_page_loaded"
                ofType:@"html"]);
 
-  std::string url_string = "file://" + path + "?url=" + expected_url +
+  std::string url_string = "file://" + path + "?file=" + expected_url +
                            "&garbage=http://still-not-that-one.com";
   GURL result_url = [ErrorPageHelper
       failedNavigationURLFromErrorPageFileURL:GURL(url_string)];
@@ -63,7 +106,7 @@ TEST_F(ErrorPageHelperTest, FailedNavigationURLFromErrorPageFileURLNoQuery) {
 // current page isn't correct.
 TEST_F(ErrorPageHelperTest, FailedNavigationURLFromErrorPageFileURLWrongPath) {
   std::string url_string =
-      "file://not-the-correct-path.com?file=http://potential-url.com";
+      "file://not-the-correct-path.com?url=http://potential-url.com";
   GURL result_url = [ErrorPageHelper
       failedNavigationURLFromErrorPageFileURL:GURL(url_string)];
   EXPECT_TRUE(result_url.is_empty());
@@ -77,7 +120,7 @@ TEST_F(ErrorPageHelperTest,
       pathForResource:@"error_page_loaded"
                ofType:@"html"]);
 
-  std::string url_string = "http://" + path + "?file=http://potential-url.com";
+  std::string url_string = "http://" + path + "?url=http://potential-url.com";
   GURL result_url = [ErrorPageHelper
       failedNavigationURLFromErrorPageFileURL:GURL(url_string)];
   EXPECT_TRUE(result_url.is_empty());