IDEA-87116 Cancel push if merge conflicts occur during auto-update while pushing

* Introduce several new GitUpdateResults for different situations, including SUCCESS_WITH_RESOLVED_CONFLICTS for the one from the bugreport.
* Return GitUpdateResult from GitUpdateProcess.
* In GitPusher if update happened with conflict resolving, don't proceed with push but show a notification.

plugins/git4idea/src/git4idea/push/GitPusher.java

@@ -15,6 +15,7 @@
  */
 package git4idea.push;
 
+import com.intellij.notification.Notification;
 import com.intellij.notification.NotificationType;
 import com.intellij.openapi.components.ServiceManager;
 import com.intellij.openapi.diagnostic.Logger;
@@ -45,6 +46,7 @@ import git4idea.repo.GitRepository;
 import git4idea.repo.GitRepositoryManager;
 import git4idea.settings.GitPushSettings;
 import git4idea.update.GitUpdateProcess;
+import git4idea.update.GitUpdateResult;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
@@ -546,12 +548,31 @@ public final class GitPusher {
   
   private boolean update(@NotNull Collection<GitRepository> rootsToUpdate, @NotNull UpdateMethod updateMethod) {
     GitUpdateProcess.UpdateMethod um = updateMethod == UpdateMethod.MERGE ? GitUpdateProcess.UpdateMethod.MERGE : GitUpdateProcess.UpdateMethod.REBASE;
-    boolean updateResult = new GitUpdateProcess(myProject, myProgressIndicator, new HashSet<GitRepository>(rootsToUpdate),
+    GitUpdateResult updateResult = new GitUpdateProcess(myProject, myProgressIndicator, new HashSet<GitRepository>(rootsToUpdate),
                                                 UpdatedFiles.create()).update(um);
     for (GitRepository repository : rootsToUpdate) {
       repository.getRoot().refresh(true, true);
     }
-    return updateResult;
+    if (updateResult == GitUpdateResult.SUCCESS) {
+      return true;
+    }
+    else if (updateResult == GitUpdateResult.SUCCESS_WITH_RESOLVED_CONFLICTS || updateResult == GitUpdateResult.INCOMPLETE) {
+      String title = "Push cancelled";
+      String description;
+      if (updateResult == GitUpdateResult.INCOMPLETE) {
+        description = "Push has been cancelled, because not all conflicts were resolved during update.<br/>" +
+                      "Resolve the conflicts and invoke push again.";
+      }
+      else {
+        description = "Push has been cancelled, because there were conflicts during update.<br/>" +
+                      "Check that conflicts were resolved correctly, and invoke push again.";
+      }
+      new Notification(GitVcs.MINOR_NOTIFICATION.getDisplayId(), title, description, NotificationType.WARNING).notify(myProject);
+      return false;
+    }
+    else {
+      return false;
+    }
   }
 
 }

plugins/git4idea/src/git4idea/update/GitMergeUpdater.java

@@ -113,7 +113,7 @@ public class GitMergeUpdater extends GitUpdater {
       LOG.info("Conflict detected");
       final boolean allMerged =
         new MyConflictResolver(myProject, myGit, merger, myRoot).merge();
-      return allMerged ? GitUpdateResult.SUCCESS : GitUpdateResult.INCOMPLETE;
+      return allMerged ? GitUpdateResult.SUCCESS_WITH_RESOLVED_CONFLICTS : GitUpdateResult.INCOMPLETE;
     }
     else if (error == MergeError.LOCAL_CHANGES) {
       LOG.info("Local changes would be overwritten by merge");

plugins/git4idea/src/git4idea/update/GitRebaseUpdater.java

@@ -105,7 +105,7 @@ public class GitRebaseUpdater extends GitUpdater {
     if (rebaseConflictDetector.isMergeConflict()) {
       LOG.info("handleRebaseFailure merge conflict");
       final boolean allMerged = new MyConflictResolver(myProject, myGit, myRoot, myRebaser).merge();
-      return allMerged ? GitUpdateResult.SUCCESS : GitUpdateResult.INCOMPLETE;
+      return allMerged ? GitUpdateResult.SUCCESS_WITH_RESOLVED_CONFLICTS : GitUpdateResult.INCOMPLETE;
     } else if (untrackedWouldBeOverwrittenDetector.wasMessageDetected()) {
       LOG.info("handleRebaseFailure: untracked files would be overwritten by checkout");
       UntrackedFilesNotifier.notifyUntrackedFilesOverwrittenBy(myProject, ServiceManager.getService(myProject, PlatformFacade.class),

plugins/git4idea/src/git4idea/update/GitUpdateEnvironment.java

@@ -66,7 +66,7 @@ public class GitUpdateEnvironment implements UpdateEnvironment {
     GitRepositoryManager repositoryManager = getRepositoryManager(myProject);
     final GitUpdateProcess gitUpdateProcess = new GitUpdateProcess(myProject, progressIndicator,
                                                                    getRepositoriesFromRoots(repositoryManager, roots), updatedFiles);
-    boolean result = gitUpdateProcess.update(GitUpdateProcess.UpdateMethod.READ_FROM_SETTINGS);
+    boolean result = gitUpdateProcess.update(GitUpdateProcess.UpdateMethod.READ_FROM_SETTINGS).isSuccess();
     return new GitUpdateSession(result);
   }
 

plugins/git4idea/src/git4idea/update/GitUpdateProcess.java

@@ -42,6 +42,7 @@ import git4idea.repo.GitBranchTrackInfo;
 import git4idea.repo.GitRepository;
 import git4idea.stash.GitChangesSaver;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 import java.util.Collection;
 import java.util.HashMap;
@@ -67,7 +68,7 @@ public class GitUpdateProcess {
   private final GitChangesSaver mySaver;
 
   private final Map<VirtualFile, GitBranchPair> myTrackedBranches = new HashMap<VirtualFile, GitBranchPair>();
-  private boolean myResult;
+  private GitUpdateResult myResult;
   private final Map<VirtualFile, GitUpdater> myUpdaters;
   private final Collection<VirtualFile> myRootsToSave;
 
@@ -94,12 +95,7 @@ public class GitUpdateProcess {
   /**
    * Checks if update is possible, saves local changes and updates all roots.
    * In case of error shows notification and returns false. If update completes without errors, returns true.
-   */
-  public boolean update() {
-    return update(UpdateMethod.READ_FROM_SETTINGS);
-  }
-
-  /**
+   *
    * Perform update on all roots.
    * 0. Blocks reloading project on external change, saving/syncing on frame deactivation.
    * 1. Checks if update is possible (rebase/merge in progress, no tracked branches...) and provides merge dialog to solve problems.
@@ -110,18 +106,19 @@ public class GitUpdateProcess {
    * local changes are not restored.
    *
    */
-  public boolean update(final UpdateMethod updateMethod) {
+  @NotNull
+  public GitUpdateResult update(final UpdateMethod updateMethod) {
     LOG.info("update started|" + updateMethod);
     String oldText = myProgressIndicator.getText();
     myProgressIndicator.setText("Updating...");
 
     // check if update is possible
     if (checkRebaseInProgress() || isMergeInProgress() || areUnmergedFiles() || !checkTrackedBranchesConfigured()) {
-      return false;
+      return GitUpdateResult.NOT_READY;
     }
 
     if (!fetchAndNotify()) {
-      return false;
+      return GitUpdateResult.NOT_READY;
     }
 
     GitComplexProcess.Operation updateOperation = new GitComplexProcess.Operation() {
@@ -135,7 +132,8 @@ public class GitUpdateProcess {
     return myResult;
   }
 
-  private boolean updateImpl(UpdateMethod updateMethod, ContinuationContext context) {
+  @NotNull
+  private GitUpdateResult updateImpl(UpdateMethod updateMethod, ContinuationContext context) {
     // define updaters for roots
     LOG.info("updateImpl: defining updaters...");
     try {
@@ -158,10 +156,10 @@ public class GitUpdateProcess {
     } catch (VcsException e) {
       LOG.info(e);
       notifyError(myProject, "Git update failed", e.getMessage(), true, e);
-      return false;
+      return GitUpdateResult.ERROR;
     }
 
-    if (myUpdaters.isEmpty()) return true;
+    if (myUpdaters.isEmpty()) return GitUpdateResult.NOTHING_TO_UPDATE;
 
     // save local changes if needed (update via merge may perform without saving).
     LOG.info("updateImpl: identifying if save is needed...");
@@ -182,13 +180,13 @@ public class GitUpdateProcess {
       notifyError(myProject, "Git update failed",
                   "Tried to save uncommitted changes in " + mySaver.getSaverName() + " before update, but failed with an error.<br/>" +
                   "Update was cancelled.", true, e);
-      return false;
+      return GitUpdateResult.ERROR;
     }
 
     // update each root
     LOG.info("updateImpl: updating...");
     boolean incomplete = false;
-    boolean success = true;
+    GitUpdateResult compoundResult = null;
     VirtualFile currentlyUpdatedRoot = null;
     try {
       for (Map.Entry<VirtualFile, GitUpdater> entry : myUpdaters.entrySet()) {
@@ -199,7 +197,7 @@ public class GitUpdateProcess {
         if (res == GitUpdateResult.INCOMPLETE) {
           incomplete = true;
         }
-        success &= res.isSuccess();
+        compoundResult = joinResults(compoundResult, res);
       }
     } catch (VcsException e) {
       String rootName = (currentlyUpdatedRoot == null) ? "" : currentlyUpdatedRoot.getName();
@@ -207,7 +205,7 @@ public class GitUpdateProcess {
       notifyImportantError(myProject, "Error updating " + rootName,
                            "Updating " + rootName + " failed with an error: " + e.getLocalizedMessage());
     } finally {
-      if (incomplete || !success) {
+      if (incomplete || !!compoundResult.isSuccess()) {
         mySaver.notifyLocalChangesAreNotRestored();
       }
       else {
@@ -215,7 +213,15 @@ public class GitUpdateProcess {
         restoreLocalChanges(context);
       }
     }
-    return success;
+    return compoundResult;
+  }
+
+  @NotNull
+  private static GitUpdateResult joinResults(@Nullable GitUpdateResult compoundResult, GitUpdateResult result) {
+    if (compoundResult == null) {
+      return result;
+    }
+    return compoundResult.join(result);
   }
 
   private void restoreLocalChanges(ContinuationContext context) {

plugins/git4idea/src/git4idea/update/GitUpdateResult.java

@@ -15,19 +15,43 @@
  */
 package git4idea.update;
 
+import org.jetbrains.annotations.NotNull;
+
 /**
  * @author Kirill Likhodedov
  */
 public enum GitUpdateResult {
-  SUCCESS,
-  /** User cancelled update, everything that has changed was rolled back (git rebase/merge --abort) */
-  CANCEL,
-  /** exception happened during update */
-  ERROR,
+  /** Nothing to update. */
+  NOTHING_TO_UPDATE(1),
+  /** Successful update, without merge conflict resolution during update. */
+  SUCCESS(2),
+  /** Update introduced a merge conflict, that was immediately resolved by user. */
+  SUCCESS_WITH_RESOLVED_CONFLICTS(3),
   /** Update introduced a merge conflict that wasn't immediately resolved. */
-  INCOMPLETE;
+  INCOMPLETE(4),
+  /** User cancelled update, everything that has changed was rolled back (git rebase/merge --abort) */
+  CANCEL(5),
+  /** An error happened during update */
+  ERROR(6),
+  /** Update is not possible due to a configuration error or because of a failed fetch. */
+  NOT_READY(7);
+
+  private final int myPriority;
+
+  GitUpdateResult(int priority) {
+    myPriority = priority;
+  }
 
   public boolean isSuccess() {
-    return this == SUCCESS || this == INCOMPLETE;
+    return this == SUCCESS || this == SUCCESS_WITH_RESOLVED_CONFLICTS || this == INCOMPLETE || this == NOTHING_TO_UPDATE;
   }
+
+  @NotNull
+  public GitUpdateResult join(@NotNull GitUpdateResult next) {
+    if (myPriority >= next.myPriority) {
+      return this;
+    }
+    return next;
+  }
+
 }