Removed the compile flag check for enabling expat, James Clark's XML parser. Now, expat can be enabled dynamically at run-time on the Windows and Unix platforms by setting the EXPAT environment variable to 1. On the Mac, create a file called EXPAT in the directory from which you run viewer.exe or apprunner.exe. This dynamic switch is only temporary. Once the bugs associated with expat's parsing of XUL files or XML errors in the XUL files are fixed, the expat parser will become the default.

htmlparser/src/nsWellFormedDTD.cpp

@@ -36,10 +36,7 @@
 #include "nsIHTMLContentSink.h"
 #include "nsHTMLTokenizer.h"
 #include "nsXMLTokenizer.h"
-
-#ifdef  EXPAT
 #include "nsExpatTokenizer.h"
-#endif
 
 #include "prenv.h"  //this is here for debug reasons...
 #include "prtypes.h"  //this is here for debug reasons...
@@ -50,7 +47,7 @@
 #include <direct.h> //this is here for debug reasons...
 #endif
 #include "prmem.h"
-
+#include "nsSpecialSystemDirectory.h"
 
 static NS_DEFINE_IID(kISupportsIID, NS_ISUPPORTS_IID);                 
 static NS_DEFINE_IID(kIDTDIID,      NS_IDTD_IID);
@@ -330,20 +327,31 @@ nsITokenRecycler* CWellFormedDTD::GetTokenRecycler(void){
 nsITokenizer* CWellFormedDTD::GetTokenizer(void) {
   if(!mTokenizer) {
     PRBool  theExpatState=PR_FALSE;
-
-#ifdef EXPAT
+#ifndef XP_MAC
     char* theEnvString = PR_GetEnv("EXPAT");
     if(theEnvString){
       if(('1'==theEnvString[0]) || ('Y'==toupper(theEnvString[0]))) {
         theExpatState=PR_TRUE;  //this indicates that the EXPAT flag was found in the environment.
       }
     }
-    if(theExpatState)
-      mTokenizer=(nsHTMLTokenizer*)new nsExpatTokenizer();
-    else mTokenizer=(nsHTMLTokenizer*)new nsXMLTokenizer();
 #else
-    mTokenizer=(nsHTMLTokenizer*)new nsXMLTokenizer();
+	// Check for the existence of a file called EXPAT in the current directory
+	nsSpecialSystemDirectory expatFile(nsSpecialSystemDirectory::OS_CurrentProcessDirectory);
+	expatFile += "EXPAT";
+	theExpatState = expatFile.Exists();
 #endif
+    if(theExpatState) {
+      mTokenizer=(nsHTMLTokenizer*)new nsExpatTokenizer();
+#ifdef DEBUG
+	  printf("Using Expat for parsing XML...\n");
+#endif
+    }      
+    else {
+      mTokenizer=(nsHTMLTokenizer*)new nsXMLTokenizer();
+#ifdef DEBUG
+	  printf("Using internal parser for parsing XML...\n");
+#endif
+    }
   }
   return mTokenizer;
 }

parser/htmlparser/src/nsWellFormedDTD.cpp

@@ -36,10 +36,7 @@
 #include "nsIHTMLContentSink.h"
 #include "nsHTMLTokenizer.h"
 #include "nsXMLTokenizer.h"
-
-#ifdef  EXPAT
 #include "nsExpatTokenizer.h"
-#endif
 
 #include "prenv.h"  //this is here for debug reasons...
 #include "prtypes.h"  //this is here for debug reasons...
@@ -50,7 +47,7 @@
 #include <direct.h> //this is here for debug reasons...
 #endif
 #include "prmem.h"
-
+#include "nsSpecialSystemDirectory.h"
 
 static NS_DEFINE_IID(kISupportsIID, NS_ISUPPORTS_IID);                 
 static NS_DEFINE_IID(kIDTDIID,      NS_IDTD_IID);
@@ -330,20 +327,31 @@ nsITokenRecycler* CWellFormedDTD::GetTokenRecycler(void){
 nsITokenizer* CWellFormedDTD::GetTokenizer(void) {
   if(!mTokenizer) {
     PRBool  theExpatState=PR_FALSE;
-
-#ifdef EXPAT
+#ifndef XP_MAC
     char* theEnvString = PR_GetEnv("EXPAT");
     if(theEnvString){
       if(('1'==theEnvString[0]) || ('Y'==toupper(theEnvString[0]))) {
         theExpatState=PR_TRUE;  //this indicates that the EXPAT flag was found in the environment.
       }
     }
-    if(theExpatState)
-      mTokenizer=(nsHTMLTokenizer*)new nsExpatTokenizer();
-    else mTokenizer=(nsHTMLTokenizer*)new nsXMLTokenizer();
 #else
-    mTokenizer=(nsHTMLTokenizer*)new nsXMLTokenizer();
+	// Check for the existence of a file called EXPAT in the current directory
+	nsSpecialSystemDirectory expatFile(nsSpecialSystemDirectory::OS_CurrentProcessDirectory);
+	expatFile += "EXPAT";
+	theExpatState = expatFile.Exists();
 #endif
+    if(theExpatState) {
+      mTokenizer=(nsHTMLTokenizer*)new nsExpatTokenizer();
+#ifdef DEBUG
+	  printf("Using Expat for parsing XML...\n");
+#endif
+    }      
+    else {
+      mTokenizer=(nsHTMLTokenizer*)new nsXMLTokenizer();
+#ifdef DEBUG
+	  printf("Using internal parser for parsing XML...\n");
+#endif
+    }
   }
   return mTokenizer;
 }