Bug 1325876 - Add a pref for showing internal error page for HTTP responses with error codes (4xx, 5xx) and Content-Length: 0 instead of blank page r=manuel,necko-reviewers,fluent-reviewers,jesup,bolsson,valentin,kershaw

Differential Revision: https://phabricator.services.mozilla.com/D220193

browser/locales/en-US/chrome/overrides/appstrings.properties

@@ -6,6 +6,7 @@ malformedURI2=Please check that the URL is correct and try again.
 fileNotFound=Firefox can’t find the file at %S.
 fileAccessDenied=The file at %S is not readable.
 # %S is replaced by the uri host
+httpErrorPage=%S sent back an error.
 serverError=%S might have a temporary problem or it could have moved.
 dnsNotFound2=We can’t connect to the server at %S.
 basicHttpAuthDisabled=Someone pretending to be the site could try to steal things like your username, password, or email.

docshell/base/nsDocShell.cpp

@@ -3354,6 +3354,9 @@ nsDocShell::DisplayLoadError(nsresult aError, nsIURI* aURI,
       nestedURI = do_QueryInterface(tempURI);
     }
     error = "unknownProtocolFound";
+  } else if (NS_ERROR_NET_EMPTY_RESPONSE == aError) {
+    NS_ENSURE_ARG_POINTER(aURI);
+    error = "httpErrorPage";
   } else if (NS_ERROR_NET_ERROR_RESPONSE == aError) {
     NS_ENSURE_ARG_POINTER(aURI);
     error = "serverError";
@@ -6111,6 +6114,7 @@ nsresult nsDocShell::FilterStatusForErrorPage(
 
   if (aStatus == NS_ERROR_NET_TIMEOUT ||
       aStatus == NS_ERROR_NET_TIMEOUT_EXTERNAL ||
+      aStatus == NS_ERROR_NET_EMPTY_RESPONSE ||
       aStatus == NS_ERROR_NET_ERROR_RESPONSE ||
       aStatus == NS_ERROR_PROXY_GATEWAY_TIMEOUT ||
       aStatus == NS_ERROR_REDIRECT_LOOP ||

dom/locales/en-US/chrome/appstrings.properties

@@ -6,6 +6,7 @@ malformedURI2=Please check that the URL is correct and try again.
 fileNotFound=The file %S cannot be found. Please check the location and try again.
 fileAccessDenied=The file at %S is not readable.
 # %S is replaced by the uri host
+httpErrorPage=%S sent back an error.
 serverError=%S might have a temporary problem or it could have moved.
 dnsNotFound2=%S could not be found. Please check the name and try again.
 basicHttpAuthDisabled=Someone pretending to be the site could try to steal your info. Your connection settings could also be set up incorrectly.

js/xpconnect/src/xpc.msg

@@ -158,6 +158,7 @@ XPC_MSG_DEF(NS_ERROR_NET_TIMEOUT_EXTERNAL           , "The request has been canc
 XPC_MSG_DEF(NS_ERROR_OFFLINE                        , "The requested action could not be completed in the offline state")
 XPC_MSG_DEF(NS_ERROR_PORT_ACCESS_NOT_ALLOWED        , "Establishing a connection to an unsafe or otherwise banned port was prohibited")
 XPC_MSG_DEF(NS_ERROR_NET_RESET                      , "The connection was established, but no data was ever received")
+XPC_MSG_DEF(NS_ERROR_NET_EMPTY_RESPONSE             , "The connection was established, but the browser received an empty page with an error response")
 XPC_MSG_DEF(NS_ERROR_NET_ERROR_RESPONSE             , "The connection was established, but the browser received an error response from the server")
 XPC_MSG_DEF(NS_ERROR_NET_INTERRUPT                  , "The connection was established, but the data transfer was interrupted")
 XPC_MSG_DEF(NS_ERROR_NET_PARTIAL_TRANSFER           , "A transfer was only partially done when it completed")

modules/libpref/init/StaticPrefList.yaml

@@ -1584,6 +1584,15 @@
   value: false
   mirror: always
 
+# If false, show internal error page for HTTP responses with error
+# codes (4xx, 5xx) and "Content-Length": 0 instead of blank page
+# See https://bugzilla.mozilla.org/show_bug.cgi?id=1325876#c32 for why this
+# is disabled on Android.
+- name: browser.http.blank_page_with_error_response.enabled
+  type: bool
+  value: true
+  mirror: always
+
 # The minimum area for a rect to be included in a wireframe, in CSS pixels.
 #
 # The current value of 50 is pretty arbitrary, and will be tuned as we refine

toolkit/content/aboutNetError.mjs

@@ -46,6 +46,7 @@ const KNOWN_ERROR_TITLE_IDS = new Set([
   "unsafeContentType-title",
   "netReset-title",
   "netTimeout-title",
+  "httpErrorPage-title",
   "serverError-title",
   "unknownProtocolFound-title",
   "proxyConnectFailure-title",
@@ -773,8 +774,7 @@ function getNetErrorDescParts() {
     case "connectionFailure":
     case "netInterrupt":
     case "netReset":
-    case "netTimeout":
+    case "netTimeout": {
-    case "serverError": {
       let errorTags = [
         ["li", "neterror-load-error-try-again"],
         ["li", "neterror-load-error-connection"],
@@ -786,6 +786,10 @@ function getNetErrorDescParts() {
       return errorTags;
     }
 
+    case "httpErrorPage": // 4xx
+      return [["li", "neterror-http-error-page"]];
+    case "serverError": // 5xx
+      return [["li", "neterror-load-error-try-again"]];
     case "blockedByCOOP": {
       return [
         ["p", "certerror-blocked-by-corp-headers-description"],

toolkit/locales/en-US/toolkit/neterror/certError.ftl

@@ -127,6 +127,7 @@ contentEncodingError-title = Content Encoding Error
 unsafeContentType-title = Unsafe File Type
 netReset-title = The connection was reset
 netTimeout-title = The connection has timed out
+httpErrorPage-title = Looks like there’s a problem with this site
 serverError-title = Looks like there’s a problem with this site
 unknownProtocolFound-title = The address wasn’t understood
 proxyConnectFailure-title = The proxy server is refusing connections

toolkit/locales/en-US/toolkit/neterror/netError.ftl

@@ -44,6 +44,8 @@ neterror-load-error-firewall = If your computer or network is protected by a fir
 # This warning is only shown on macOS Sequoia and later (see bug 1929377)
 neterror-load-osx-permission = If you are trying to load a local network page, please check that { -brand-short-name } has been granted Local Network permissions in the macOS Privacy & Security settings.
 
+neterror-http-error-page = Check to make sure you’ve typed the website address correctly.
+
 neterror-captive-portal = You must log in to this network before you can access the internet.
 
 # Variables:

tools/lint/fluent-lint/exclusions.yml

@@ -63,6 +63,7 @@ ID01:
         - unsafeContentType-title
         - netReset-title
         - netTimeout-title
+        - httpErrorPage-title
         - serverError-title
         - unknownProtocolFound-title
         - proxyConnectFailure-title

uriloader/base/nsURILoader.cpp

@@ -131,6 +131,23 @@ NS_IMETHODIMP nsDocumentOpenInfo::OnStartRequest(nsIRequest* request) {
     if (204 == responseCode || 205 == responseCode) {
       return NS_BINDING_ABORTED;
     }
+
+    if (!mozilla::StaticPrefs::
+            browser_http_blank_page_with_error_response_enabled()) {
+      // Bug 1325876: Show internal error page for HTTP responses with error
+      // codes (4xx, 5xx) and "Content-Length": 0 instead of blank page
+      int64_t contentLength = 0;
+      rv = httpChannel->GetContentLength(&contentLength);
+
+      if (NS_FAILED(rv) || contentLength <= 0) {
+        if (responseCode >= 500) {
+          return NS_ERROR_NET_ERROR_RESPONSE;
+        }
+        if (responseCode >= 400) {
+          return NS_ERROR_NET_EMPTY_RESPONSE;
+        }
+      }
+    }
   }
 
   //

xpcom/base/ErrorList.py

@@ -327,6 +327,8 @@ with modules["NETWORK"]:
     errors["NS_ERROR_NET_RESET"] = FAILURE(20)
     # The connection was established, but browser received an error response from the server
     errors["NS_ERROR_NET_ERROR_RESPONSE"] = FAILURE(35)
+    # The connection was established, but browser received an empty page with 4xx, 5xx error response
+    errors["NS_ERROR_NET_EMPTY_RESPONSE"] = FAILURE(36)
     # The connection was established, but the data transfer was interrupted.
     errors["NS_ERROR_NET_INTERRUPT"] = FAILURE(71)
     # The connection attempt to a proxy failed.