pmd: fix #943 PreserveStackTrace false positive if a StringBuffer exists

pmd/etc/changelog.txt

@@ -15,6 +15,7 @@ New Java rule:
 
 ????? ??, 2013 - 5.0.3:
 
+Fixed bug  943: PreserveStackTrace false positive if a StringBuffer exists
 Fixed bug  945: PMD generates RuleSets it cannot read.
 Fixed bug  958: Intermittent NullPointerException while loading XPath node attributes
 Fixed bug  968: Issues with JUnit4 @Test annotation with expected exception (Thanks to Yiannis Paschalidis)

pmd/src/main/java/net/sourceforge/pmd/lang/java/rule/design/PreserveStackTraceRule.java

@@ -74,10 +74,12 @@ public class PreserveStackTraceRule extends AbstractJavaRule {
 	                    if ((child instanceof ASTName) && !target.equals(child.getImage()) && !child.hasImageEqualTo(target + FILL_IN_STACKTRACE)) {
 	                        Map<VariableNameDeclaration, List<NameOccurrence>> vars = ((ASTName) child).getScope().getVariableDeclarations();
 		                    for (VariableNameDeclaration decl: vars.keySet()) {
-		                        args = decl.getNode().jjtGetParent()
-		                                .getFirstDescendantOfType(ASTArgumentList.class);
-		                        if (args != null) {
-		                            ck(data, target, throwStatement, args);
+		                        if (decl.getImage().equals(child.getImage())) {
+    		                        args = decl.getNode().jjtGetParent()
+    		                                .getFirstDescendantOfType(ASTArgumentList.class);
+    		                        if (args != null) {
+    		                            ck(data, target, throwStatement, args);
+    		                        }
 		                        }
 		                    }
 	                    } else if (child instanceof ASTClassOrInterfaceType){

pmd/src/test/resources/net/sourceforge/pmd/lang/java/rule/design/xml/PreserveStackTrace.xml

@@ -427,4 +427,26 @@ class MultiCatch {
         <source-type>java 1.7</source-type>
     </test-code>
 
+    <test-code>
+        <description>#943 PreserveStackTrace false positive if a StringBuffer exists</description>
+        <expected-problems>0</expected-problems>
+        <code><![CDATA[
+public class Stuff {
+    @SuppressWarnings("unused")
+    public void doStuff() throws SomeException {
+        try {
+            doMoreStuff();
+        } catch (Exception e) {
+            StringBuffer irrelevantSB = new StringBuffer("Irrelevant").append(" string").append(" buffer");
+            SomeException someException = new SomeException(e);
+            throw someException;
+        }
+    }
+
+    private void doMoreStuff() {
+        // Stuff happens
+    }
+}
+        ]]></code>
+    </test-code>
 </test-data>