Fix potential gc bug

cfis · cfis · commit a7fa224d5bf2 · 2026-04-05T21:47:12.000-07:00
diff --git a/ext/libxml/ruby_xml_writer.c b/ext/libxml/ruby_xml_writer.c
@@ -196,6 +196,7 @@ static VALUE rxml_writer_doc(VALUE klass)
 {
     xmlDocPtr doc;
     rxml_writer_object* rwo;
+    VALUE output, result;
 
     rwo = ALLOC(rxml_writer_object);
     rwo->buffer = NULL;
@@ -207,9 +208,12 @@ static VALUE rxml_writer_doc(VALUE klass)
     {
         rxml_raise(xmlGetLastError());
     }
-    rwo->output = rxml_document_wrap(doc);
+    output = rxml_document_wrap(doc);
+    rwo->output = output;
 
-    return rxml_writer_wrap(rwo);
+    result = rxml_writer_wrap(rwo);
+    RB_GC_GUARD(output);
+    return result;
 }
 
 /* ===== public instance methods ===== */

Original file line number	Diff line number	Diff line change
`@@ -196,6 +196,7 @@ static VALUE rxml_writer_doc(VALUE klass)`
`196`	`196`	`{`
`197`	`197`	`xmlDocPtr doc;`
`198`	`198`	`rxml_writer_object* rwo;`
	`199`	`+ VALUE output, result;`
`199`	`200`
`200`	`201`	`rwo = ALLOC(rxml_writer_object);`
`201`	`202`	`rwo->buffer = NULL;`
`@@ -207,9 +208,12 @@ static VALUE rxml_writer_doc(VALUE klass)`
`207`	`208`	`{`
`208`	`209`	`rxml_raise(xmlGetLastError());`
`209`	`210`	`}`
`210`		`- rwo->output = rxml_document_wrap(doc);`
	`211`	`+ output = rxml_document_wrap(doc);`
	`212`	`+ rwo->output = output;`
`211`	`213`
`212`		`- return rxml_writer_wrap(rwo);`
	`214`	`+ result = rxml_writer_wrap(rwo);`
	`215`	`+ RB_GC_GUARD(output);`
	`216`	`+ return result;`
`213`	`217`	`}`
`214`	`218`
`215`	`219`	`/* ===== public instance methods ===== */`