IDEA-54491 diff: ask if there are left unprocessed changes on merge apply

platform/platform-impl/src/com/intellij/openapi/diff/impl/incrementalMerge/ui/MergePanel2.java

@@ -53,13 +53,14 @@ import com.intellij.openapi.fileTypes.FileType;
 import com.intellij.openapi.fileTypes.FileTypes;
 import com.intellij.openapi.project.Project;
 import com.intellij.openapi.ui.DialogBuilder;
+import com.intellij.openapi.ui.DialogWrapper;
 import com.intellij.openapi.ui.LabeledComponent;
+import com.intellij.openapi.ui.Messages;
 import com.intellij.openapi.util.Disposer;
 import com.intellij.openapi.util.text.StringUtil;
-import com.intellij.openapi.vfs.LocalFileSystem;
 import com.intellij.openapi.vfs.VirtualFile;
 import com.intellij.ui.EditorNotificationPanel;
-import com.intellij.util.diff.FilesTooBigForDiffException;
+import com.intellij.util.containers.Convertor;
 import gnu.trove.TIntHashSet;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
@@ -371,7 +372,20 @@ public class MergePanel2 implements DiffViewer {
       data.customizeToolbar(myPanel.resetToolbar());
       myPanel.registerToolbarActions();
       if ( data instanceof MergeRequestImpl && myBuilder != null){
-        ((MergeRequestImpl)data).setActions(myBuilder, this);
+        Convertor<DialogWrapper, Boolean> preOkHook = new Convertor<DialogWrapper, Boolean>() {
+          @Override
+          public Boolean convert(DialogWrapper dialog) {
+            ChangeCounter counter = ChangeCounter.getOrCreate(myMergeList);
+            int changes = counter.getChangeCounter();
+            int conflicts = counter.getConflictCounter();
+            if (changes == 0 && conflicts == 0) return true;
+            return Messages.showYesNoDialog(dialog.getRootPane(),
+                                            DiffBundle.message("merge.dialog.apply.partially.resolved.changes.confirmation.message", changes, conflicts),
+                                            DiffBundle.message("apply.partially.resolved.merge.dialog.title"),
+                                            Messages.getQuestionIcon()) == Messages.YES;
+          }
+        };
+        ((MergeRequestImpl)data).setActions(myBuilder, this, preOkHook);
       }
     }
     finally {

platform/platform-impl/src/com/intellij/openapi/diff/impl/mergeTool/MergeRequestImpl.java

@@ -28,6 +28,7 @@ import com.intellij.openapi.ui.DialogBuilder;
 import com.intellij.openapi.ui.DialogWrapper;
 import com.intellij.openapi.ui.Messages;
 import com.intellij.openapi.vfs.VirtualFile;
+import com.intellij.util.containers.Convertor;
 import org.jetbrains.annotations.NonNls;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
@@ -189,6 +190,10 @@ public class MergeRequestImpl extends MergeRequest {
   }
 
   public void setActions(final DialogBuilder builder, MergePanel2 mergePanel) {
+    setActions(builder, mergePanel, null);
+  }
+
+  public void setActions(final DialogBuilder builder, MergePanel2 mergePanel, final Convertor<DialogWrapper, Boolean> preOkHook) {
     builder.removeAllActions(); // otherwise dialog will get default actions (OK, Cancel)
 
     if (myOkButtonPresentation != null) {
@@ -200,6 +205,7 @@ public class MergeRequestImpl extends MergeRequest {
       builder.setOkOperation(new Runnable() {
         @Override
         public void run() {
+          if (preOkHook != null && !preOkHook.convert(builder.getDialogWrapper())) return;
           myOkButtonPresentation.run(builder.getDialogWrapper());
         }
       });

platform/platform-resources-en/src/messages/DiffBundle.properties

@@ -67,6 +67,8 @@ merge.partial.diff.action.name.0.1=Compare left and middle panel contents
 merge.partial.diff.action.name.1.2=Compare middle and right panel contents
 merge.dialog.exit.without.applying.changes.confirmation.message=Are you sure you want to exit without applying changes?
 cancel.visual.merge.dialog.title=Cancel Visual Merge
+merge.dialog.apply.partially.resolved.changes.confirmation.message=There are {0, choice, 0#|1#one change|2#{0, number} changes}{0, choice, 0#|1#'{1, choice, 0#|1# and }'}{1, choice, 0#|1#one conflict|2#{1, number} conflicts} left unprocessed.\nAre you sure you want to save changes and finish merging?
+apply.partially.resolved.merge.dialog.title=Apply Changes
 merge.all.changes.have.processed.save.and.finish.confirmation.text=All changes have been processed.\nWould you like to save changes and finish merging?
 all.changes.processed.dialog.title=All Changes Processed
 merge.save.and.finish.button=Save and &Finish