Implements commands to recompute merge with git merge-file

extensions/git/package.json

@@ -609,6 +609,18 @@
         "command": "git.openMergeEditor",
         "title": "%command.git.openMergeEditor%",
         "category": "Git"
+      },
+      {
+        "command": "git.runGitMerge",
+        "title": "%command.git.runGitMerge%",
+        "category": "Git",
+        "enablement": "isMergeEditor"
+      },
+      {
+        "command": "git.runGitMergeDiff3",
+        "title": "%command.git.runGitMergeDiff3%",
+        "category": "Git",
+        "enablement": "isMergeEditor"
       }
     ],
     "keybindings": [
@@ -1568,6 +1580,16 @@
           "when": "config.git.enabled && !git.missing && !isInDiffEditor && !isMergeEditor && resource in git.mergeChanges"
         }
       ],
+      "mergeEditor/result/context": [
+        {
+          "command": "git.runGitMerge",
+          "when": "isMergeEditor"
+        },
+        {
+          "command": "git.runGitMergeDiff3",
+          "when": "isMergeEditor"
+        }
+      ],
       "scm/change/title": [
         {
           "command": "git.stageChange",

extensions/git/package.nls.json

@@ -104,6 +104,8 @@
 	"command.api.getRemoteSources": "Get Remote Sources",
 	"command.git.acceptMerge": "Accept Merge",
 	"command.git.openMergeEditor": "Open in Merge Editor",
+	"command.git.runGitMerge": "Compute Conflicts With Git",
+	"command.git.runGitMergeDiff3": "Compute Conflicts With Git (Diff3)",
 	"config.enabled": "Whether git is enabled.",
 	"config.path": "Path and filename of the git executable, e.g. `C:\\Program Files\\Git\\bin\\git.exe` (Windows). This can also be an array of string values containing multiple paths to look up.",
 	"config.autoRepositoryDetection": "Configures when repositories should be automatically detected.",

extensions/git/src/commands.ts

@@ -1134,6 +1134,48 @@ export class CommandCenter {
 		}
 	}
 
+	@command('git.runGitMerge')
+	async runGitMergeNoDiff3(): Promise<void> {
+		await this.runGitMerge(false);
+	}
+
+	@command('git.runGitMergeDiff3')
+	async runGitMergeDiff3(): Promise<void> {
+		await this.runGitMerge(true);
+	}
+
+	private async runGitMerge(diff3: boolean): Promise<void> {
+		const { activeTab } = window.tabGroups.activeTabGroup;
+		if (!activeTab) {
+			return;
+		}
+
+		const input = activeTab.input as { base: Uri; input1: Uri; input2: Uri; result: Uri };
+
+		const result = await this.git.mergeFile({
+			basePath: input.base.fsPath,
+			input1Path: input.input1.fsPath,
+			input2Path: input.input2.fsPath,
+			diff3,
+		});
+
+		const doc = workspace.textDocuments.find(doc => doc.uri.toString() === input.result.toString());
+		if (!doc) {
+			return;
+		}
+		const e = new WorkspaceEdit();
+
+		e.replace(
+			input.result,
+			new Range(
+				new Position(0, 0),
+				new Position(doc.lineCount, 0),
+			),
+			result
+		);
+		await workspace.applyEdit(e);
+	}
+
 	private async _stageChanges(textEditor: TextEditor, changes: LineChange[]): Promise<void> {
 		const modifiedDocument = textEditor.document;
 		const modifiedUri = modifiedDocument.uri;

extensions/git/src/git.ts

@@ -656,6 +656,27 @@ export class Git {
 	private log(output: string): void {
 		this._onOutput.emit('log', output);
 	}
+
+	async mergeFile(options: { input1Path: string; input2Path: string; basePath: string; diff3?: boolean }): Promise<string> {
+		const args = ['merge-file', '-p', options.input1Path, options.basePath, options.input2Path];
+		if (options.diff3) {
+			args.push('--diff3');
+		} else {
+			args.push('--no-diff3');
+		}
+
+		try {
+			const result = await this.exec('', args);
+			return result.stdout;
+		} catch (err) {
+			if (typeof err.stdout === 'string') {
+				// The merge had conflicts, stdout still contains the merged result (with conflict markers)
+				return err.stdout;
+			} else {
+				throw err;
+			}
+		}
+	}
 }
 
 export interface Commit {

src/vs/workbench/services/actions/common/menusExtensionPoint.ts

@@ -291,7 +291,11 @@ const apiMenus: IAPIMenu[] = [
 		description: localize('webview.context', "The webview context menu"),
 		proposed: 'contribWebviewContext'
 	},
-
+	{
+		key: 'mergeEditor/result/context',
+		id: MenuId.MergeInputResultToolbar,
+		description: localize('menus.mergeEditorResult', "The result toolbar of the merge editor"),
+	},
 ];
 
 namespace schema {