fix assert logic

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Merge branch 'master' of github.com:IMBIGFISH4/xml2 into IMBIGFISH4-master
2026-07-23 04:03:00 +04:00 · 2026-05-23 16:10:29 -07:00 · 2026-05-23 16:04:26 -07:00 · 2026-05-23 16:02:58 -07:00 · 2026-03-09 17:53:04 -07:00 · 2026-03-09 17:32:22 -07:00
2 changed files with 25 additions and 5 deletions
@@ -114,6 +114,9 @@ distribution.
 	#define TIXML_VSNPRINTF	vsnprintf
 	static inline int TIXML_VSCPRINTF( const char* format, va_list va )
 	{
+	    if (!format) {
+	        return 0;
+	    }
 		int len = vsnprintf( 0, 0, format, va );
 		TIXMLASSERT( len >= 0 );
 		return len;
@@ -831,7 +834,17 @@ XMLNode::XMLNode( XMLDocument* doc ) :

 XMLNode::~XMLNode()
 {
-    DeleteChildren();
+    // Fast path: this node is dying, so maintaining _firstChild/_lastChild and
+    // sibling _prev/_next links is unnecessary. Only _parent must be zeroed to
+    // satisfy the MarkInUse assertion inside DeleteNode.
+    XMLNode *currentChild = _firstChild;
+    while (currentChild != NULL) {
+        XMLNode *next = currentChild->_next;
+        currentChild->_parent = 0;
+        DeleteNode(currentChild);
+        currentChild = next;
+    }
+
    if ( _parent ) {
        _parent->Unlink( this );
    }
@@ -2344,9 +2357,10 @@ static FILE* callfopen( const char* filepath, const char* mode )
    return fp;
 }

-void XMLDocument::DeleteNode( XMLNode* node )	{
-    TIXMLASSERT( node );
-    TIXMLASSERT(node->_document == this );
+void XMLDocument::DeleteNode( XMLNode* node )	{   
+    if(node == 0) {
+        return; // check for null pointer
+    }
    if (node->_parent) {
        node->_parent->DeleteChild( node );
    }
@@ -2025,7 +2025,13 @@ int main( int argc, const char ** argv )
 		XMLTest("Parse nested elements with pedantic whitespace", false, doc.Error());
 		XMLTest("Pedantic whitespace", true, 0 == doc.RootElement()->FirstChildElement()->GetText());
 	}
-
+	//Check the robustness of the DeleteNode function in handling null pointers.
+	{
+		XMLDocument doc;
+		doc.DeleteNode(nullptr);
+		XMLTest("DeleteNode with null pointer", true, doc.Error() == XML_SUCCESS);
+	}
+		
 	// Check sample xml can be parsed with pedantic mode
 	{
 		XMLDocument doc(true, PEDANTIC_WHITESPACE);
Author	SHA1	Message	Date
Lee Thomason	5ce9f9a3a7	fix assert logic	2026-05-23 16:10:29 -07:00
Lee Thomason	682fda289f	add comment	2026-05-23 16:04:26 -07:00
Lee Thomason	e6a464942f	Merge branch 'master' of github.com:IMBIGFISH4/xml2 into IMBIGFISH4-master	2026-05-23 16:02:58 -07:00
Lee Thomason	98137e6936	Merge branch 'master' of github.com:leethomason/tinyxml2	2026-03-09 17:53:04 -07:00
zhthhh	aba13c50bf	Fix issue #1048 : Add null pointer check in XMLDocument::DeleteNode (#1057 ) - Add null pointer check in XMLDocument::DeleteNode() method - Add test case to verify null pointer handling - Prevents segmentation fault when calling DeleteNode(nullptr)	2026-03-09 17:32:22 -07:00
sbaluja	e48a1310fe	Add null check for format in TIXML_VSCPRINTF (#1064 )	2026-03-09 17:31:36 -07:00
Michael Mishin	fc99428a82	Improved XMLNode::~XMLNode perfomance XMLNode::~XMLNode uses interface method DeleteChildren(), which iteratively removes the first child until the list is empty. Each single removal performs additional checks and keeps _firstChild and _lastChild links in a consistent state. This leads to a performance penalty. The proposed patch solves this problem by iterating the list of the children and directly destroying them without keeping links in a consistent state. The performance boost we gained on xmltest is: - 3% for my laptop (x86_64) - 9% for bananapi f3 board (riscv64)	2025-07-29 16:30:58 +03:00