Add "auto" option for create base branch (#5860)

Fixes #5859

Author: alexr00

package.json

@@ -439,12 +439,13 @@
 				},
 				"githubPullRequests.createDefaultBaseBranch": {
 					"type": "string",
-					"enum": ["repositoryDefault", "createdFromBranch"],
+					"enum": ["repositoryDefault", "createdFromBranch", "auto"],
 					"markdownEnumDescriptions": [
 						"%githubPullRequests.createDefaultBaseBranch.repositoryDefault%",
-						"%githubPullRequests.createDefaultBaseBranch.createdFromBranch%"
+						"%githubPullRequests.createDefaultBaseBranch.createdFromBranch%",
+						"%githubPullRequests.createDefaultBaseBranch.auto%"
 					],
-					"default": "createdFromBranch",
+					"default": "auto",
 					"markdownDescription": "%githubPullRequests.createDefaultBaseBranch.description%"
 				},
 				"githubIssues.ignoreMilestones": {

package.nls.json

@@ -85,6 +85,7 @@
 	"githubPullRequests.createDefaultBaseBranch.description": "Controls what the base branch picker defaults to when creating a pull request",
 	"githubPullRequests.createDefaultBaseBranch.repositoryDefault": "The default branch of the repository",
 	"githubPullRequests.createDefaultBaseBranch.createdFromBranch": "The branch that the current branch was created from, if known",
+	"githubPullRequests.createDefaultBaseBranch.auto": "When the current repository is a fork, this will work like \"repositoryDefault\". Otherwise, it will work like \"createdFromBranch\".",
 	"githubIssues.ignoreMilestones.description": "An array of milestones titles to never show issues from.",
 	"githubIssues.createIssueTriggers.description": "Strings that will cause the 'Create issue from comment' code action to show.",
 	"githubIssues.createIssueTriggers.items": "String that enables the 'Create issue from comment' code action. Should not contain whitespace.",

src/github/createPRViewProviderNew.ts

@@ -307,12 +307,18 @@ export class CreatePullRequestViewProviderNew extends WebviewViewBase implements
 		return this._alreadyInitializing;
 	}
 
-	private async detectBaseMetadata(defaultCompareBranch: string): Promise<BaseBranchMetadata | undefined> {
-		if (vscode.workspace.getConfiguration(PR_SETTINGS_NAMESPACE).get<'repositoryDefault' | 'createdFromBranch'>(CREATE_BASE_BRANCH) !== 'createdFromBranch') {
+	private async detectBaseMetadata(defaultCompareBranch: Branch, owner: string, repositoryName: string): Promise<BaseBranchMetadata | undefined> {
+		const settingValue = vscode.workspace.getConfiguration(PR_SETTINGS_NAMESPACE).get<'repositoryDefault' | 'createdFromBranch' | 'auto'>(CREATE_BASE_BRANCH);
+		if (!defaultCompareBranch.name || settingValue === 'repositoryDefault') {
 			return undefined;
 		}
+		const githubRepo = this._folderRepositoryManager.findRepo(repo => compareIgnoreCase(repo.remote.owner, owner) === 0 && compareIgnoreCase(repo.remote.repositoryName, repositoryName) === 0);
+		if (settingValue === 'auto' && (await githubRepo?.getMetadata())?.fork) {
+			return undefined;
+		}
+
 		try {
-			const baseFromProvider = await this._folderRepositoryManager.repository.getBranchBase(defaultCompareBranch);
+			const baseFromProvider = await this._folderRepositoryManager.repository.getBranchBase(defaultCompareBranch.name);
 			if (baseFromProvider?.name) {
 				const repo = this._folderRepositoryManager.findRepo(repo => repo.remote.remoteName === baseFromProvider.remote);
 				if (repo) {
@@ -332,7 +338,7 @@ export class CreatePullRequestViewProviderNew extends WebviewViewBase implements
 	private async doInitializeParams(): Promise<CreateParamsNew> {
 		const defaultCompareBranch = await this._folderRepositoryManager.repository.getBranch(this._defaultCompareBranch);
 		const [detectedBaseMetadata, remotes, defaultOrigin] = await Promise.all([
-			this.detectBaseMetadata(defaultCompareBranch.name!),
+			this.detectBaseMetadata(defaultCompareBranch, this.model.compareOwner, this.model.repositoryName),
 			this._folderRepositoryManager.getGitHubRemotes(),
 			this._folderRepositoryManager.getOrigin(defaultCompareBranch)]);