8351967: JFR: AnnotationIterator should handle num_annotations = 0

Markus Grönlund · Markus Grönlund · commit 2eecf159afac · 2025-03-17T09:56:10.000Z
Reviewed-by: egahlin
diff --git a/src/hotspot/share/jfr/instrumentation/jfrEventClassTransformer.cpp b/src/hotspot/share/jfr/instrumentation/jfrEventClassTransformer.cpp
@@ -338,7 +338,7 @@ class AnnotationIterator : public StackObj {
                                                                      _buffer(_limit > 2 ? ar->adr_at(2) : nullptr),
                                                                      _current(0),
                                                                      _next(0) {
-    if (_buffer != nullptr) {
+    if (_limit >= 2) {
       _limit -= 2; // subtract sizeof(u2) number of annotations field
     }
   }

Original file line number	Diff line number	Diff line change
`@@ -338,7 +338,7 @@ class AnnotationIterator : public StackObj {`
`338`	`338`	`_buffer(_limit > 2 ? ar->adr_at(2) : nullptr),`
`339`	`339`	`_current(0),`
`340`	`340`	`_next(0) {`
`341`		`- if (_buffer != nullptr) {`
	`341`	`+ if (_limit >= 2) {`
`342`	`342`	`_limit -= 2; // subtract sizeof(u2) number of annotations field`
`343`	`343`	`}`
`344`	`344`	`}`