Add end index to details string implementation for Ruby SubstringRope

bjfish · thurka · commit 9efce0256087 · 2020-05-21T19:54:41.000+02:00
diff --git a/visualvm/heapviewer.truffle/src/org/graalvm/visualvm/heapviewer/truffle/lang/ruby/RubyDetailsProvider.java b/visualvm/heapviewer.truffle/src/org/graalvm/visualvm/heapviewer/truffle/lang/ruby/RubyDetailsProvider.java
@@ -108,8 +108,11 @@ public String getDetailsString(String className, Instance instance, Heap heap) {
             }
             byteOffset = ((Integer) offset).intValue();
 
-            if (childString.length() > byteOffset) {
-                return childString.substring(byteOffset);
+            Object length = instance.getValueOfField("byteLength");
+            int byteLength = ((Integer) length).intValue();
+
+            if (childString.length() > byteOffset && childString.length() >= byteOffset + byteLength) {
+                return childString.substring(byteOffset, byteOffset + byteLength);
             }
         }
         if (ENCODING_MASK.equals(className)) {

Original file line number	Diff line number	Diff line change
`@@ -108,8 +108,11 @@ public String getDetailsString(String className, Instance instance, Heap heap) {`
`108`	`108`	`}`
`109`	`109`	`byteOffset = ((Integer) offset).intValue();`
`110`	`110`
`111`		`- if (childString.length() > byteOffset) {`
`112`		`- return childString.substring(byteOffset);`
	`111`	`+ Object length = instance.getValueOfField("byteLength");`
	`112`	`+ int byteLength = ((Integer) length).intValue();`
	`113`	`+`
	`114`	`+ if (childString.length() > byteOffset && childString.length() >= byteOffset + byteLength) {`
	`115`	`+ return childString.substring(byteOffset, byteOffset + byteLength);`
`113`	`116`	`}`
`114`	`117`	`}`
`115`	`118`	`if (ENCODING_MASK.equals(className)) {`