Support commit.template config property

* Prefill empty commit message with the commit template specified via
commit.template (if configured)
* Refresh commit message template if message is empty and user
stages/unstages files
* Affects staging view and commit dialog

Bug: 446355
Change-Id: Ic9ea86dafdcc00cbf7846f0b1bbeb49782f03fa3

6 files changed, 49 insertions, 4 deletions

diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/UIText.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/UIText.java
index 2a3d68871e..6c77b349a5 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/UIText.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/UIText.java
@@ -2445,6 +2445,9 @@ public class UIText extends NLS {
 	public static String CommitAction_CommittingFailed;
 
 	/** */
+	public static String CommitAction_CommitTemplateFailed;
+
+	/** */
 	public static String CommitAction_errorComputingDiffs;
 
 	/** */
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/commit/CommitHelper.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/commit/CommitHelper.java
index f17c52f464..fcaf68da4d 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/commit/CommitHelper.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/commit/CommitHelper.java
@@ -20,6 +20,8 @@ import java.io.IOException;
 
 import org.eclipse.egit.ui.Activator;
 import org.eclipse.egit.ui.internal.UIText;
+import org.eclipse.jgit.errors.ConfigInvalidException;
+import org.eclipse.jgit.lib.CommitConfig;
 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.lib.PersonIdent;
@@ -28,6 +30,7 @@ import org.eclipse.jgit.lib.RepositoryState;
 import org.eclipse.jgit.lib.UserConfig;
 import org.eclipse.jgit.revwalk.RevCommit;
 import org.eclipse.jgit.revwalk.RevWalk;
+import org.eclipse.jgit.util.StringUtils;
 import org.eclipse.osgi.util.NLS;
 import org.eclipse.swt.widgets.Text;
 
@@ -37,7 +40,7 @@ import org.eclipse.swt.widgets.Text;
  */
 public class CommitHelper {
 
-	private Repository repository;
+	final private Repository repository;
 
 	boolean canCommit;
 
@@ -55,6 +58,8 @@ public class CommitHelper {
 
 	private String commitMessage;
 
+	private String commitTemplate;
+
 	/**
 	 * @param repository
 	 */
@@ -98,6 +103,34 @@ public class CommitHelper {
 		if (isCherryPickResolved) {
 			author = getCherryPickOriginalAuthor(mergeRepository);
 		}
+
+	}
+
+	/**
+	 * @return true if there is no commit message but a commit template
+	 */
+	public boolean shouldUseCommitTemplate() {
+		return StringUtils.isEmptyOrNull(getCommitMessage())
+				&& getCommitTemplate() != null;
+	}
+
+	/**
+	 * @return commit message template
+	 */
+	public String getCommitTemplate() {
+		if (commitTemplate == null && repository != null) {
+			CommitConfig commitConfig = repository.getConfig()
+					.get(CommitConfig.KEY);
+			try {
+				commitTemplate = commitConfig
+						.getCommitTemplateContent(repository);
+			} catch (IOException | ConfigInvalidException e) {
+				Activator.handleError(UIText.CommitAction_CommitTemplateFailed,
+						e, true);
+			}
+		}
+
+		return commitTemplate;
 	}
 
 	private static RevCommit getHeadCommit(Repository repository) {
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/commit/CommitUI.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/commit/CommitUI.java
index 44f6cd9b8e..7693cf9770 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/commit/CommitUI.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/commit/CommitUI.java
@@ -184,7 +184,11 @@ public class CommitUI  {
 		commitDialog.setAuthor(commitHelper.getAuthor());
 		commitDialog.setCommitter(commitHelper.getCommitter());
 		commitDialog.setAllowToChangeSelection(!commitHelper.isMergedResolved && !commitHelper.isCherryPickResolved);
-		commitDialog.setCommitMessage(commitHelper.getCommitMessage());
+		if (commitHelper.shouldUseCommitTemplate()) {
+			commitDialog.setCommitMessage(commitHelper.getCommitTemplate());
+		} else {
+			commitDialog.setCommitMessage(commitHelper.getCommitMessage());
+		}
 
 		if (commitDialog.open() != IDialogConstants.OK_ID)
 			return false;
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/dialogs/CommitMessageComponent.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/dialogs/CommitMessageComponent.java
index f6eee65811..3c6cd9e0c8 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/dialogs/CommitMessageComponent.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/dialogs/CommitMessageComponent.java
@@ -800,7 +800,7 @@ public class CommitMessageComponent {
 	String calculateCommitMessage(
 			CommitMessageWithCaretPosition messageWithCaretPosition) {
 		if (commitMessage != null) {
-			// special case for merge / cherry-pick
+			// special case for merge / cherry-pick / existing message template
 			return commitMessage;
 		}
 
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/staging/StagingView.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/staging/StagingView.java
index 0d7911fa64..cf14782a5a 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/staging/StagingView.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/staging/StagingView.java
@@ -4368,7 +4368,11 @@ public class StagingView extends ViewPart
 		commitMessageComponent.enableListeners(false);
 		commitMessageComponent.resetState();
 		commitMessageComponent.setAuthor(helper.getAuthor());
-		commitMessageComponent.setCommitMessage(helper.getCommitMessage());
+		if (helper.shouldUseCommitTemplate()) {
+			commitMessageComponent.setCommitMessage(helper.getCommitTemplate());
+		} else {
+			commitMessageComponent.setCommitMessage(helper.getCommitMessage());
+		}
 		commitMessageComponent.setCommitter(helper.getCommitter());
 		commitMessageComponent.setHeadCommit(getCommitId(helper
 				.getPreviousCommit()));
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/uitext.properties b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/uitext.properties
index 01e2678774..b5bde2cef5 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/uitext.properties
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/uitext.properties
@@ -856,6 +856,7 @@ CommitAction_amendNotPossible=Commit/amend not possible. Possible causes\:\n\n-
 CommitAction_cannotCommit=Cannot commit now
 CommitAction_CommittingChanges=Committing changes
 CommitAction_CommittingFailed=Committing failed
+CommitAction_CommitTemplateFailed=Evaluation of commit template failed
 CommitAction_errorComputingDiffs=Error occurred computing Git commit diffs
 CommitAction_errorRetrievingCommit=Error occurred retrieving last commit
 CommitAction_noFilesToCommit=No files to commit