diff --git a/mozilla/docshell/base/nsDocShell.cpp b/mozilla/docshell/base/nsDocShell.cpp
index 4c64b0db5d7..7e16a0528f0 100644
--- a/mozilla/docshell/base/nsDocShell.cpp
+++ b/mozilla/docshell/base/nsDocShell.cpp
@@ -2319,31 +2319,31 @@ NS_IMETHODIMP nsDocShell::CreateFixupURI(const PRUnichar* aStringURI,
       return NS_OK;
 
    // See if a protocol needs to be added
-   PRInt32 colon = -1;
+   PRInt32 colon = uriString.FindChar(':');
    PRInt32 fSlash = uriString.FindChar('/');
-   PRUnichar port;
+   PRUnichar port = nsnull;;
    // if no scheme (protocol) is found, assume http.
-   if((colon=uriString.FindChar(':') == -1) ||// no colon at all
-      ((fSlash > -1) && (colon > fSlash)) ||// the only colon comes after the first slash
-      ((colon < (((PRInt32)uriString.Length())-1)) && // the first char after the first colon is a digit (i.e. a port)
-       ((port=uriString.CharAt(colon+1)) <= '9') && (port > '0'))) 
-      {
-      // find host name
-      PRInt32 hostPos = uriString.FindCharInSet("./:");
-      if(hostPos == -1) 
-         hostPos = uriString.Length();
+   if (colon == -1 || fSlash == -1 || (fSlash > -1) && (colon > fSlash)) {
+      if (colon < (((PRInt32)uriString.Length())-1)) {
+         if (colon != -1) port = uriString.CharAt(colon+1);
+         if (colon == -1 || uriString.IsDigit(port)) {
+            // find host name
+            PRInt32 hostPos = uriString.FindCharInSet("./:");
+            if (hostPos == -1) 
+               hostPos = uriString.Length();
 
-      // extract host name
-      nsAutoString hostSpec;
-      uriString.Left(hostSpec, hostPos);
-
-      // insert url spec corresponding to host name
-      if(hostSpec.EqualsIgnoreCase("ftp")) 
-         uriString.InsertWithConversion("ftp://", 0, 6);
-      else 
-         uriString.InsertWithConversion("http://", 0, 7);
-      } // end if colon
+            // extract host name
+            nsAutoString hostSpec;
+            uriString.Left(hostSpec, hostPos);
 
+            // insert url spec corresponding to host name
+            if (hostSpec.EqualsIgnoreCase("ftp")) 
+               uriString.InsertWithConversion("ftp://", 0, 6);
+            else 
+               uriString.InsertWithConversion("http://", 0, 7);
+         } 
+      }
+   } // end if colon
    return NS_NewURI(aURI, uriString.GetUnicode(), nsnull);
 }