false positives for null dereferences

src/main/org/apache/tools/ant/UnknownElement.java

@@ -646,7 +646,8 @@ public class UnknownElement extends Task {
             return false;
         }
         for (int i = 0; i < childrenSize; ++i) {
-            UnknownElement child = (UnknownElement) children.get(i);
+            // children cannot be null childrenSize would have been 0
+            UnknownElement child = (UnknownElement) children.get(i); //NOSONAR
             if (!child.similar(other.children.get(i))) {
                 return false;
             }

src/main/org/apache/tools/ant/taskdefs/MacroInstance.java

@@ -197,9 +197,12 @@ public class MacroInstance extends Task implements DynamicAttribute, TaskContain
                     }
                     break;
                 case STATE_EXPECT_NAME:
+                    // macroName cannot be null as this state is only
+                    // ever reached from STATE_EXPECT_BRACKET after it
+                    // has been set
                     if (ch == '}') {
                         state = STATE_NORMAL;
-                        String name = macroName.toString().toLowerCase(Locale.ENGLISH);
+                        String name = macroName.toString().toLowerCase(Locale.ENGLISH); //NOSONAR
                         String value = (String) macroMapping.get(name);
                         if (value == null) {
                             ret.append("@{");
@@ -210,7 +213,7 @@ public class MacroInstance extends Task implements DynamicAttribute, TaskContain
                         }
                         macroName = null;
                     } else {
-                        macroName.append(ch);
+                        macroName.append(ch); //NOSONAR
                     }
                     break;
                 default:
@@ -224,8 +227,11 @@ public class MacroInstance extends Task implements DynamicAttribute, TaskContain
                 ret.append('@');
                 break;
             case STATE_EXPECT_NAME:
+                // macroName cannot be null as this state is only
+                // ever reached from STATE_EXPECT_BRACKET after it
+                // has been set
                 ret.append("@{");
-                ret.append(macroName.toString());
+                ret.append(macroName.toString()); //NOSONAR
                 break;
             default:
                 break;

src/main/org/apache/tools/zip/ZipFile.java

@@ -1038,12 +1038,12 @@ public class ZipFile implements Closeable {
         @Override
         public boolean equals(final Object other) {
             if (super.equals(other)) {
-                // super.equals would return false if other were not an Entry
+                // super.equals would return false if other were null or not an Entry
                 final Entry otherEntry = (Entry) other;
                 return offsetEntry.headerOffset
-                        == otherEntry.offsetEntry.headerOffset
+                        == otherEntry.offsetEntry.headerOffset //NOSONAR
                     && offsetEntry.dataOffset
-                        == otherEntry.offsetEntry.dataOffset;
+                        == otherEntry.offsetEntry.dataOffset; //NOSONAR
             }
             return false;
         }