diff --git a/mozilla/expat/xmlparse/xmlparse.c b/mozilla/expat/xmlparse/xmlparse.c
index d3033c3a8cc..b9c67c172f8 100644
--- a/mozilla/expat/xmlparse/xmlparse.c
+++ b/mozilla/expat/xmlparse/xmlparse.c
@@ -1278,13 +1278,8 @@ doContent(XML_Parser parser,
 	  return XML_ERROR_NO_MEMORY;
 	entity = (ENTITY *)lookup(&dtd.generalEntities, name, 0);
 	poolDiscard(&dtd.pool);
-	if (!entity) {
-	  if (dtd.complete || dtd.standalone)
-	    return XML_ERROR_UNDEFINED_ENTITY;
-	  if (defaultHandler)
-	    reportDefault(parser, enc, s, next);
-	  break;
-	}
+	if (!entity)
+	  return XML_ERROR_UNDEFINED_ENTITY;
 	if (entity->open)
 	  return XML_ERROR_RECURSIVE_ENTITY_REF;
 	if (entity->notation)
@@ -2959,8 +2954,8 @@ appendAttributeValue(XML_Parser parser, const ENCODING *enc, int isCdata,
 	  if (dtd.complete) {
 	    if (enc == encoding)
 	      eventPtr = ptr;
-	    return XML_ERROR_UNDEFINED_ENTITY;
 	  }
+	  return XML_ERROR_UNDEFINED_ENTITY;
 	}
 	else if (entity->open) {
 	  if (enc == encoding)
diff --git a/mozilla/htmlparser/src/nsExpatDriver.cpp b/mozilla/htmlparser/src/nsExpatDriver.cpp
index b0c63c3d232..daa0c818867 100644
--- a/mozilla/htmlparser/src/nsExpatDriver.cpp
+++ b/mozilla/htmlparser/src/nsExpatDriver.cpp
@@ -200,7 +200,7 @@ Driver_HandleExternalEntityRef(XML_Parser parser,
       
       XML_SetBase(entParser, (const XML_Char*) absURL.get());
 
-      while (NS_SUCCEEDED(uniIn->Read(uniBuf, 0, 1024, &readCount))) {
+      while (NS_SUCCEEDED(uniIn->Read(uniBuf, 0, 1024, &readCount)) && result) {
         if (readCount) {
           // Pass the buffer to expat for parsing
           result = XML_Parse(entParser, (char *)uniBuf,  readCount * sizeof(PRUnichar), 0);
@@ -459,7 +459,9 @@ IsLoadableDTD(const XML_Char* aFPIStr, nsCOMPtr<nsIURI>* aDTD)
   if (!isLoadable) {
     // try to see if we can map the public ID to a known local DTD
     nsXPIDLCString fileName;
-    RemapDTD(aFPIStr, fileName);
+    if (aFPIStr) {
+      RemapDTD(aFPIStr, fileName);
+    }
     if (fileName.IsEmpty()) {
       // try to see if the user has installed the DTD file -- we extract the
       // filename.ext of the DTD here. Hence, for any DTD for which we have
diff --git a/mozilla/parser/expat/lib/xmlparse.c b/mozilla/parser/expat/lib/xmlparse.c
index d3033c3a8cc..b9c67c172f8 100644
--- a/mozilla/parser/expat/lib/xmlparse.c
+++ b/mozilla/parser/expat/lib/xmlparse.c
@@ -1278,13 +1278,8 @@ doContent(XML_Parser parser,
 	  return XML_ERROR_NO_MEMORY;
 	entity = (ENTITY *)lookup(&dtd.generalEntities, name, 0);
 	poolDiscard(&dtd.pool);
-	if (!entity) {
-	  if (dtd.complete || dtd.standalone)
-	    return XML_ERROR_UNDEFINED_ENTITY;
-	  if (defaultHandler)
-	    reportDefault(parser, enc, s, next);
-	  break;
-	}
+	if (!entity)
+	  return XML_ERROR_UNDEFINED_ENTITY;
 	if (entity->open)
 	  return XML_ERROR_RECURSIVE_ENTITY_REF;
 	if (entity->notation)
@@ -2959,8 +2954,8 @@ appendAttributeValue(XML_Parser parser, const ENCODING *enc, int isCdata,
 	  if (dtd.complete) {
 	    if (enc == encoding)
 	      eventPtr = ptr;
-	    return XML_ERROR_UNDEFINED_ENTITY;
 	  }
+	  return XML_ERROR_UNDEFINED_ENTITY;
 	}
 	else if (entity->open) {
 	  if (enc == encoding)
diff --git a/mozilla/parser/htmlparser/src/nsExpatDriver.cpp b/mozilla/parser/htmlparser/src/nsExpatDriver.cpp
index b0c63c3d232..daa0c818867 100644
--- a/mozilla/parser/htmlparser/src/nsExpatDriver.cpp
+++ b/mozilla/parser/htmlparser/src/nsExpatDriver.cpp
@@ -200,7 +200,7 @@ Driver_HandleExternalEntityRef(XML_Parser parser,
       
       XML_SetBase(entParser, (const XML_Char*) absURL.get());
 
-      while (NS_SUCCEEDED(uniIn->Read(uniBuf, 0, 1024, &readCount))) {
+      while (NS_SUCCEEDED(uniIn->Read(uniBuf, 0, 1024, &readCount)) && result) {
         if (readCount) {
           // Pass the buffer to expat for parsing
           result = XML_Parse(entParser, (char *)uniBuf,  readCount * sizeof(PRUnichar), 0);
@@ -459,7 +459,9 @@ IsLoadableDTD(const XML_Char* aFPIStr, nsCOMPtr<nsIURI>* aDTD)
   if (!isLoadable) {
     // try to see if we can map the public ID to a known local DTD
     nsXPIDLCString fileName;
-    RemapDTD(aFPIStr, fileName);
+    if (aFPIStr) {
+      RemapDTD(aFPIStr, fileName);
+    }
     if (fileName.IsEmpty()) {
       // try to see if the user has installed the DTD file -- we extract the
       // filename.ext of the DTD here. Hence, for any DTD for which we have