Add a flag that allows protocol handlers to indicate that they don't return any

data.  Bug 379819, patch by Ryan Jones <sciguyryan@gmail.com>, r=me, sr=biesi

content/base/src/nsNoDataProtocolContentPolicy.cpp

@@ -51,6 +51,7 @@
 #include "nsIProtocolHandler.h"
 #include "nsIIOService.h"
 #include "nsIExternalProtocolHandler.h"
+#include "nsNetUtil.h"
 
 NS_IMPL_ISUPPORTS1(nsNoDataProtocolContentPolicy, nsIContentPolicy)
 
@@ -70,9 +71,11 @@ nsNoDataProtocolContentPolicy::ShouldLoad(PRUint32 aContentType,
   if (aContentType != TYPE_DOCUMENT &&
       aContentType != TYPE_SUBDOCUMENT &&
       aContentType != TYPE_OBJECT) {
+
+    // The following are just quick-escapes for the most common cases
+    // where we would allow the content to be loaded anyway.
     nsCAutoString scheme;
     aContentLocation->GetScheme(scheme);
-    // Fast-track for the common cases
     if (scheme.EqualsLiteral("http") ||
         scheme.EqualsLiteral("https") ||
         scheme.EqualsLiteral("ftp") ||
@@ -81,19 +84,11 @@ nsNoDataProtocolContentPolicy::ShouldLoad(PRUint32 aContentType,
       return NS_OK;
     }
 
-    nsIIOService* ios = nsContentUtils::GetIOService();
-    if (!ios) {
-      // default to accept, just in case
-      return NS_OK;
-    }
-    
-    nsCOMPtr<nsIProtocolHandler> handler;
-    ios->GetProtocolHandler(scheme.get(), getter_AddRefs(handler));
-
-    nsCOMPtr<nsIExternalProtocolHandler> extHandler =
-      do_QueryInterface(handler);
-
-    if (extHandler) {
+    PRBool shouldBlock;
+    nsresult rv = NS_URIChainHasFlags(aContentLocation,
+                                      nsIProtocolHandler::URI_DOES_NOT_RETURN_DATA,
+                                      &shouldBlock);
+    if (NS_SUCCEEDED(rv) && shouldBlock) {
       *aDecision = nsIContentPolicy::REJECT_REQUEST;
     }
   }

extensions/irc/js/lib/chatzilla-service.js

@@ -269,6 +269,10 @@ if ("URI_NON_PERSISTABLE" in nsIProtocolHandler) {
   IRCProtocolHandler.prototype.protocolFlags |=
       nsIProtocolHandler.URI_NON_PERSISTABLE;
 }
+if ("URI_DOES_NOT_RETURN_DATA" in nsIProtocolHandler) {
+  IRCProtocolHandler.prototype.protocolFlags |=
+      nsIProtocolHandler.URI_DOES_NOT_RETURN_DATA;
+}
 
 IRCProtocolHandler.prototype.allowPort =
 function ircph_allowPort(port, scheme)

mailnews/compose/src/nsSmtpService.cpp

@@ -306,7 +306,7 @@ nsSmtpService::AllowPort(PRInt32 port, const char *scheme, PRBool *_retval)
 NS_IMETHODIMP nsSmtpService::GetProtocolFlags(PRUint32 *result)
 {
     *result = URI_NORELATIVE | ALLOWS_PROXY | URI_LOADABLE_BY_ANYONE |
-        URI_NON_PERSISTABLE;
+        URI_NON_PERSISTABLE | URI_DOES_NOT_RETURN_DATA;
     return NS_OK;
 }
 

netwerk/base/public/nsIProtocolHandler.idl

@@ -214,6 +214,13 @@ interface nsIProtocolHandler : nsISupports
      * it unsuitable for saving to a local file.
      */
     const unsigned long URI_NON_PERSISTABLE = (1<<10);
+
+    /**
+     * Channels using this protocol never call OnDataAvailable
+     * on the listener passed to AsyncOpen and they therefore
+     * do not return any data that we can use.
+     */
+    const unsigned long URI_DOES_NOT_RETURN_DATA = (1<<11);
     
     /**
      * This protocol handler can be proxied via a proxy (socks or http)

uriloader/exthandler/nsExternalProtocolHandler.cpp

@@ -565,7 +565,7 @@ NS_IMETHODIMP nsExternalProtocolHandler::GetProtocolFlags(PRUint32 *aUritype)
 {
     // Make it norelative since it is a simple uri
     *aUritype = URI_NORELATIVE | URI_NOAUTH | URI_LOADABLE_BY_ANYONE |
-        URI_NON_PERSISTABLE;
+        URI_NON_PERSISTABLE | URI_DOES_NOT_RETURN_DATA;
     return NS_OK;
 }