merged from trunk: Fixed bug 1481051 - false + UnusedNullCheckInEquals (and other false positives too)

git-svn-id: https://pmd.svn.sourceforge.net/svnroot/pmd/branches/pmd/4.2.x@6440 51baf565-9d33-0410-a72c-fc3788e3496d

pmd/etc/changelog.txt

@@ -1,5 +1,7 @@
 ???? - 4.2.4:
 
+Fixed bug 1481051 - false + UnusedNullCheckInEquals (and other false positives too)
+
 August 31, 2008 - 4.2.3:
 
 JavaCC generated artifacts updated to JavaCC 4.1d1.

pmd/regress/test/net/sourceforge/pmd/rules/basic/xml/UnusedNullCheckInEquals.xml

@@ -50,6 +50,33 @@ public class Foo {
   if (x != null && "Foo".equals(y)) {} 
   if (y.equals(x)) {} 
  }
+}
+     ]]></code>
+    </test-code>
+    <test-code>
+        <description><![CDATA[
+var is not used in equals() call
+     ]]></description>
+        <expected-problems>0</expected-problems>
+        <code><![CDATA[
+public class Foo {
+ public void bar() {
+  if (c != null && A.b(c).equals(d)) {}
+ }
+}
+     ]]></code>
+    </test-code>
+    <test-code>
+        <description><![CDATA[
+[ 1481051 ] false + UnusedNullCheckInEquals
+     ]]></description>
+        <expected-problems>0</expected-problems>
+        <code><![CDATA[
+public class Foo {
+ public void bar() {
+if(o1!=null && o1[0] != null && o2[0].getName()!=null && o2[0].getName().equals(o1[0].getName()) ){ }
+if(o1!=null && o2.equals(o1.getName()) ){ }
+ }
 }
      ]]></code>
     </test-code>

pmd/rulesets/basic.xml

@@ -873,8 +873,8 @@ public class Foo {
         <value>
         <![CDATA[
 //PrimarySuffix[@Image='equals' and not(../PrimaryPrefix/Literal)]
- /../PrimarySuffix/Arguments/ArgumentList/Expression
- /PrimaryExpression/PrimaryPrefix
+ /following-sibling::PrimarySuffix/Arguments/ArgumentList/Expression
+ /PrimaryExpression[count(PrimarySuffix)=0]/PrimaryPrefix
  /Name[@Image = ./../../../../../../../../../../Expression/ConditionalAndExpression
  /EqualityExpression[@Image="!=" and count(./preceding-sibling::*)=0 and
  ./PrimaryExpression/PrimaryPrefix/Literal/NullLiteral]