Bug #38374 --> more updates for external helper application support. (NOT PART OF THE BUILD)

code review will come when this is done and gets turned on.

Use the 4.x windows registry information in an effort to figure out the correct file extension
for a particular content type. This is necessary because we need the file extension to figure out
which helper app to use, not the content type.

Pass the file extension to be associated with this content type to the external content handler when
we create it.

uriloader/exthandler/win/nsOSHelperAppService.cpp

@@ -99,8 +99,9 @@ nsresult nsExternalApplication::LaunchApplication(nsIFile * aTempFile)
   return rv;
 }
 
-// helper method:
+// helper methods: forward declarations...
 BYTE * GetValueBytes( HKEY hKey, const char *pValueName);
+nsresult GetExtensionFrom4xRegistryInfo(const char * aMimeType, nsCString& aFileExtension);
 
 nsOSHelperAppService::nsOSHelperAppService() : nsExternalHelperAppService()
 {
@@ -139,18 +140,31 @@ NS_IMETHODIMP nsOSHelperAppService::DoContent(const char *aMimeContentType, nsIU
   // ACK!!! we've done all this work to discover the content type just to find out that windows
   // registery uses the extension to figure out the right helper app....that's a bummer...
 
-  nsCOMPtr<nsIURL> url = do_QueryInterface(aURI);
-
-  if (url)
+  nsCAutoString fileExtension;
+  // this is just a hack for now...look up the content type and find a file
+  // extension using information 4.x put in the windows registry...
+  nsresult rv = GetExtensionFrom4xRegistryInfo(aMimeContentType, fileExtension);
+  if (FAILED(rv))
   {
-     nsXPIDLCString fileExtension;
-     url->GetFileExtension(getter_Copies(fileExtension));
+    // if we couldn't find one, don't give up yet! Try and see if there is an extension in the 
+    // url itself...
+    nsCOMPtr<nsIURL> url = do_QueryInterface(aURI);
+
+    if (url)
+    {
+      nsXPIDLCString extenion;
+      url->GetFileExtension(getter_Copies(extenion));
     
-     nsCAutoString reg = ".";  
-     reg.Append(fileExtension);
+     fileExtension = ".";  
+     fileExtension.Append(extenion);
+    }
+  } // if we couldn't get extension information from the registry...
+
+  if (!fileExtension.IsEmpty())
+  {
      nsCAutoString appName;
      HKEY hKey;
-     LONG err = ::RegOpenKeyEx( HKEY_CLASSES_ROOT, reg, 0, KEY_QUERY_VALUE, &hKey);
+     LONG err = ::RegOpenKeyEx( HKEY_CLASSES_ROOT, fileExtension, 0, KEY_QUERY_VALUE, &hKey);
      if (err == ERROR_SUCCESS)
      {
         LPBYTE pBytes = GetValueBytes( hKey, NULL);
@@ -167,10 +181,14 @@ NS_IMETHODIMP nsOSHelperAppService::DoContent(const char *aMimeContentType, nsIU
         nsCOMPtr<nsISupports> appSupports = do_QueryInterface(application);
 
         // this code is incomplete and just here to get things started..
-        nsExternalAppHandler * handler = CreateNewExternalHandler(appSupports);
+        nsExternalAppHandler * handler = CreateNewExternalHandler(appSupports, fileExtension);
         handler->QueryInterface(NS_GET_IID(nsIStreamListener), (void **) aStreamListener);
+
+        // close the key
+       ::RegCloseKey(hKey);
+
      } // if we got an entry out of the registry...
-  } // if url
+  } // if we have a file extension
 
   return NS_OK;
 }
@@ -186,6 +204,39 @@ NS_IMETHODIMP nsOSHelperAppService::LaunchAppWithTempFile(nsIFile * aTempFile, n
     return NS_ERROR_FAILURE;
 }
 
+// We have a serious problem!! I have this content type and the windows registry only gives me
+// helper apps based on extension. Right now, we really don't have a good place to go for 
+// trying to figure out the extension for a particular mime type....One short term hack is to look
+// this information in 4.x (it's stored in the windows regsitry). 
+nsresult GetExtensionFrom4xRegistryInfo(const char * aMimeType, nsCString& aFileExtension)
+{
+   nsCAutoString command ("Software\\Netscape\\Netscape Navigator\\Suffixes");
+   nsresult rv = NS_OK;
+   HKEY hKey;
+   LONG err = ::RegOpenKeyEx( HKEY_CURRENT_USER, command, 0, KEY_QUERY_VALUE, &hKey);
+   if (err == ERROR_SUCCESS)
+   {
+      LPBYTE pBytes = GetValueBytes( hKey, aMimeType);
+      aFileExtension = ".";
+      aFileExtension.Append( (char *) pBytes);
+      
+      // this may be a comma separate list of extensions...just take the first one
+      // for now...
+
+      PRInt32 pos = aFileExtension.FindChar(',', PR_TRUE);
+      if (pos > 0) // we have a comma separated list of languages...
+        aFileExtension.Truncate(pos); // truncate everything after the first comma (including the comma)
+   
+      delete [] pBytes;
+      // close the key
+      ::RegCloseKey(hKey);
+   }
+   else
+     rv = NS_ERROR_FAILURE; // not 4.x extension mapping found!
+
+   return rv;
+}
+
 BYTE * GetValueBytes( HKEY hKey, const char *pValueName)
 {
 	LONG	err;