Treat an empty disposition string the same as it not being set. Bug 272541,

r=biesi, sr=darin

uriloader/base/nsURILoader.cpp

@@ -426,8 +426,14 @@ nsresult nsDocumentOpenInfo::DispatchContent(nsIRequest *request, nsISupports *
                                     PR_TRUE, nsnull, dispToken);
       // RFC 2183, section 2.8 says that an unknown disposition
       // value should be treated as "attachment"
+      // XXXbz this code is duplicated in GetFilenameAndExtensionFromChannel in
+      // nsExternalHelperAppService.  Factor it out!
       if (NS_FAILED(rv) || 
-          (!dispToken.LowerCaseEqualsLiteral("inline") &&
+          (// Some broken sites just send
+           // Content-Disposition: ; filename="file"
+           // screen those out here.
+           !dispToken.IsEmpty() &&
+           !dispToken.LowerCaseEqualsLiteral("inline") &&
           // Broken sites just send
           // Content-Disposition: filename="file"
           // without a disposition token... screen those out.

uriloader/exthandler/nsExternalHelperAppService.cpp

@@ -286,8 +286,14 @@ static PRBool GetFilenameAndExtensionFromChannel(nsIChannel* aChannel,
                                   nsnull, dispToken);
     // RFC 2183, section 2.8 says that an unknown disposition
     // value should be treated as "attachment"
+    // XXXbz this code is duplicated in nsDocumentOpenInfo::DispatchContent.
+    // Factor it out!  Maybe store it in the nsDocumentOpenInfo?
     if (NS_FAILED(rv) || 
-        (!dispToken.LowerCaseEqualsLiteral("inline") &&
+        (// Some broken sites just send
+         // Content-Disposition: ; filename="file"
+         // screen those out here.
+         !dispToken.IsEmpty() &&
+         !dispToken.LowerCaseEqualsLiteral("inline") &&
         // Broken sites just send
         // Content-Disposition: filename="file"
         // without a disposition token... screen those out.