fix: workspace forks shouldn't inherit promotion mode repo (#7223)

* fix: workspace forks shouldn't inherit promotion mode repo

* fix: git sync: don't default to main when talking about target branches in git

backend/windmill-api/src/workspaces.rs

@@ -2566,9 +2566,14 @@ async fn update_workspace_settings(
         WorkspaceGitSyncSettings::default()
     };
 
-    // We only keep the first git sync repo, since it is considered the main one
+    // We only keep the first git sync repo that is sync mode (use_individual_branch = false), since it is considered the main one
     // Context: see WIN-1559
-    git_sync_settings.repositories.truncate(1);
+    git_sync_settings.repositories = git_sync_settings
+        .repositories
+        .into_iter()
+        .filter(|r| !r.use_individual_branch.unwrap_or(false))
+        .take(1)
+        .collect();
 
     let serialized_config = serde_json::to_value::<WorkspaceGitSyncSettings>(git_sync_settings)
         .map_err(|err| Error::internal_err(err.to_string()))?;

frontend/src/lib/components/git_sync/DetectionFlow.svelte

@@ -12,7 +12,7 @@
 
 	const gitSyncContext = getGitSyncContext()
 	const repo = $derived(gitSyncContext.getRepository(idx))
-	let targetBranch = $state('main')
+	let targetBranch = $state<string | undefined>(undefined)
 
 	// Update target branch when repository changes
 	$effect(() => {

frontend/src/lib/components/git_sync/GitSyncContext.svelte.ts

@@ -664,12 +664,13 @@ export function createGitSyncContext(workspace: string) {
 	}
 
 	// Helper to get target branch from git resource
-	async function getTargetBranch(repo: GitSyncRepository): Promise<string> {
+	async function getTargetBranch(repo: GitSyncRepository): Promise<string | undefined> {
 		if (!repo.git_repo_resource_path) {
-			return 'main'
+			return undefined
 		}
 
 		if (repo._targetBranch) {
+			if (repo._targetBranch === '') return undefined
 			return repo._targetBranch
 		}
 
@@ -681,14 +682,15 @@ export function createGitSyncContext(workspace: string) {
 
 			// Extract branch from git resource value
 			const resourceValue = resource.value as any
-			const targetBranch = resourceValue?.branch || 'main'
+			const targetBranch = resourceValue?.branch
 
 			// Cache the result
 			repo._targetBranch = targetBranch
+			if (targetBranch === '') return undefined
 			return targetBranch
 		} catch (error) {
 			console.warn('Failed to fetch git resource for branch info:', error)
-			return 'main'
+			return undefined
 		}
 	}
 

frontend/src/lib/components/git_sync/GitSyncModeDisplay.svelte

@@ -3,7 +3,7 @@
 
 	let { mode, targetBranch, repository } = $props<{
 		mode?: 'sync' | 'promotion' | null
-		targetBranch: string
+		targetBranch: string | undefined
 		repository?: GitSyncRepository | null
 	}>()
 </script>
@@ -11,12 +11,15 @@
 <div class="text-base">
 	{#if mode === 'promotion'}
 		<div
-			><span class="font-bold">Promotion:</span> Creating branches whose promotion target is {targetBranch}</div
+			><span class="font-bold">Promotion:</span> Creating branches whose promotion target is {targetBranch? `'${targetBranch}'` :
+				"the repo's default branch"}</div
 		>
 		{#if repository?.group_by_folder}
 			<div class="text-sm text-primary mt-1">Grouped by folder</div>
 		{/if}
+	{:else if targetBranch}
+		<div><span class="font-bold">Sync:</span> Syncing back to branch '{targetBranch}'</div>
 	{:else}
-		<div><span class="font-bold">Sync:</span> Syncing back to branch {targetBranch}</div>
+		<div><span class="font-bold">Sync:</span> Syncing back to the repo's default branch</div>
 	{/if}
 </div>

frontend/src/lib/components/git_sync/GitSyncRepositoryCard.svelte

@@ -50,7 +50,7 @@
 	const validation = $derived(idx !== null ? gitSyncContext.getValidation(idx) : null)
 	const gitSyncTestJob = $derived(idx !== null ? gitSyncContext.gitSyncTestJobs?.[idx] : null)
 	let confirmingDelete = $state(false)
-	let targetBranch = $state('main') // Default to main, will be updated when resource is available
+	let targetBranch = $state<string | undefined>(undefined) // Default to main, will be updated when resource is available
 
 	// Update target branch when repository changes
 	$effect(() => {
@@ -108,12 +108,13 @@
 	)
 
 	// Determine display description based on variant and mode
+	const targetOrDefaultBranch = $derived(targetBranch ? `'${targetBranch}'` : 'repo\'s default' )
 	const displayDescription = $derived(
 		variant === 'primary-sync' || variant === 'primary-promotion'
 			? mode === 'sync'
-				? `Changes will be committed directly to the ${targetBranch} branch`
+				? `Changes will be committed directly to the ${targetOrDefaultBranch} branch`
 				: mode === 'promotion'
-					? `Changes will be made to new branches whose promotion target is ${targetBranch}`
+					? `Changes will be made to new branches whose promotion target is the ${targetOrDefaultBranch} branch`
 					: null
 			: null
 	)