Compare string objects with .equals method rather than ==

Change-Id: I6dfcd9e84e3d3519a34f27b2f24196359717b72e
diff --git a/gerrit-gwtui/src/main/java/com/google/gerrit/client/changes/PublishCommentScreen.java b/gerrit-gwtui/src/main/java/com/google/gerrit/client/changes/PublishCommentScreen.java
index 58a7042..6e9b6d6 100644
--- a/gerrit-gwtui/src/main/java/com/google/gerrit/client/changes/PublishCommentScreen.java
+++ b/gerrit-gwtui/src/main/java/com/google/gerrit/client/changes/PublishCommentScreen.java
@@ -306,7 +306,7 @@
 
       if (lastState != null && patchSetId.equals(lastState.patchSetId)
           && lastState.approvals.containsKey(label.name())) {
-        b.setValue(lastState.approvals.get(label.name()) == value);
+        b.setValue(lastState.approvals.get(label.name()).equals(value));
       } else {
         b.setValue(b.parseValue() == (prior != null ? prior : 0));
       }
diff --git a/gerrit-gwtui/src/main/java/com/google/gerrit/client/ui/Screen.java b/gerrit-gwtui/src/main/java/com/google/gerrit/client/ui/Screen.java
index 3f79a61..0cabdda 100644
--- a/gerrit-gwtui/src/main/java/com/google/gerrit/client/ui/Screen.java
+++ b/gerrit-gwtui/src/main/java/com/google/gerrit/client/ui/Screen.java
@@ -108,7 +108,7 @@
       headerText.setText(text);
       header.setVisible(true);
     }
-    if (windowTitle == null || windowTitle == old) {
+    if (windowTitle == null || windowTitle.equals(old)) {
       setWindowTitle(text);
     }
   }
diff --git a/gerrit-pgm/src/main/java/com/google/gerrit/pgm/init/Section.java b/gerrit-pgm/src/main/java/com/google/gerrit/pgm/init/Section.java
index 387b93a..6489035 100644
--- a/gerrit-pgm/src/main/java/com/google/gerrit/pgm/init/Section.java
+++ b/gerrit-pgm/src/main/java/com/google/gerrit/pgm/init/Section.java
@@ -96,7 +96,7 @@
       final boolean nullIfDefault) {
     final String ov = get(name);
     String nv = ui.readString(ov != null ? ov : dv, "%s", title);
-    if (nullIfDefault && nv == dv) {
+    if (nullIfDefault && nv.equals(dv)) {
       nv = null;
     }
     if (!eq(ov, nv)) {