fix: compare ahead/behind counts against base branch instead of remote tracking branch (#544)

apps/backend/internal/agentctl/server/process/workspace_git_status.go

@@ -126,24 +126,21 @@ func (wt *WorkspaceTracker) getGitBranchInfo(ctx context.Context, update *types.
 	return nil
 }
 
-// getAheadBehindCounts populates the Ahead/Behind fields relative to the tracking or
-// origin branch. Falls back to origin/main then origin/master when no upstream is set.
+// getAheadBehindCounts populates the Ahead/Behind fields relative to the base branch
+// (origin/main or origin/master). Always compares against the base branch rather than
+// the remote tracking branch, because after a rebase the tracking branch has stale
+// commit SHAs that produce inflated counts.
 func (wt *WorkspaceTracker) getAheadBehindCounts(ctx context.Context, update *types.GitStatusUpdate) {
-	// Use remote branch if available, otherwise fall back to origin/main or origin/master
-	// This handles worktree branches that don't have an upstream tracking branch set
-	compareRef := update.RemoteBranch
-	if compareRef == "" {
-		// Try origin/main first, then origin/master
-		checkCmd := exec.CommandContext(ctx, "git", "rev-parse", "--verify", "origin/main")
+	// Always compare against the base branch (origin/main or origin/master).
+	// Using the remote tracking branch (origin/<feature-branch>) gives wrong counts
+	// after rebase because rebased commits have new SHAs.
+	var compareRef string
+	for _, candidate := range []string{"origin/main", "origin/master"} {
+		checkCmd := exec.CommandContext(ctx, "git", "rev-parse", "--verify", candidate)
 		checkCmd.Dir = wt.workDir
 		if err := checkCmd.Run(); err == nil {
-			compareRef = "origin/main"
-		} else {
-			checkCmd2 := exec.CommandContext(ctx, "git", "rev-parse", "--verify", "origin/master")
-			checkCmd2.Dir = wt.workDir
-			if err := checkCmd2.Run(); err == nil {
-				compareRef = "origin/master"
-			}
+			compareRef = candidate
+			break
 		}
 	}
 	if compareRef == "" {

apps/backend/internal/agentctl/server/process/workspace_tracker_test.go

@@ -272,6 +272,69 @@ func TestGetGitStatus_AheadBehindWithoutUpstream(t *testing.T) {
 	}
 }
 
+// TestGetGitStatus_AheadBehindAfterRebase verifies that ahead/behind counts
+// reflect divergence from the base branch (origin/main), not the remote tracking
+// branch. After a rebase, the remote tracking branch has stale SHAs, so comparing
+// against it produces inflated counts.
+func TestGetGitStatus_AheadBehindAfterRebase(t *testing.T) {
+	repoDir, cleanup := setupTestRepo(t)
+	defer cleanup()
+
+	log := newTestLogger(t)
+	wt := NewWorkspaceTracker(repoDir, log)
+	ctx := context.Background()
+
+	// Create a feature branch with upstream tracking
+	runGit(t, repoDir, "checkout", "-b", "feature-rebase")
+	runGit(t, repoDir, "push", "-u", "origin", "feature-rebase")
+
+	// Make 2 commits on the feature branch
+	writeFile(t, repoDir, "feature1.txt", "feature 1")
+	runGit(t, repoDir, "add", ".")
+	runGit(t, repoDir, "commit", "-m", "Feature commit 1")
+
+	writeFile(t, repoDir, "feature2.txt", "feature 2")
+	runGit(t, repoDir, "add", ".")
+	runGit(t, repoDir, "commit", "-m", "Feature commit 2")
+
+	// Push feature commits so remote tracking branch has them
+	runGit(t, repoDir, "push")
+
+	// Switch to main, add commits, push
+	runGit(t, repoDir, "checkout", "main")
+	for i := 0; i < 5; i++ {
+		writeFile(t, repoDir, "main"+string(rune('0'+i))+".txt", "main content")
+		runGit(t, repoDir, "add", ".")
+		runGit(t, repoDir, "commit", "-m", "Main commit")
+	}
+	runGit(t, repoDir, "push")
+
+	// Switch back to feature and rebase onto main
+	runGit(t, repoDir, "checkout", "feature-rebase")
+	runGit(t, repoDir, "fetch", "origin")
+	runGit(t, repoDir, "rebase", "origin/main")
+
+	// Now: local feature-rebase has 2 feature commits on top of main (rebased)
+	// But origin/feature-rebase still points to old pre-rebase commits
+	// git rev-list --left-right --count feature-rebase...origin/feature-rebase
+	// would show ~7 ahead (2 rebased + 5 main commits), not 2
+
+	status, err := wt.getGitStatus(ctx)
+	if err != nil {
+		t.Fatalf("failed to get git status: %v", err)
+	}
+
+	// Should be 2 ahead of origin/main (the 2 feature commits)
+	if status.Ahead != 2 {
+		t.Errorf("expected ahead=2, got %d", status.Ahead)
+	}
+
+	// Should be 0 behind origin/main (just rebased)
+	if status.Behind != 0 {
+		t.Errorf("expected behind=0, got %d", status.Behind)
+	}
+}
+
 // TestFilterLocalCommits_PullAndResetScenario tests the exact scenario where:
 // 1. Session starts at commit X
 // 2. Upstream (origin/main) gets new commits

apps/backend/internal/agentctl/types/streams/git.go

@@ -25,10 +25,10 @@ type GitStatusUpdate struct {
 	// Renamed contains paths of renamed files.
 	Renamed []string `json:"renamed"`
 
-	// Ahead is the number of commits ahead of the remote branch.
+	// Ahead is the number of commits ahead of the base branch (origin/main).
 	Ahead int `json:"ahead"`
 
-	// Behind is the number of commits behind the remote branch.
+	// Behind is the number of commits behind the base branch (origin/main).
 	Behind int `json:"behind"`
 
 	// Branch is the current local branch name.

apps/web/components/task/task-top-bar.tsx

@@ -251,13 +251,15 @@ function TopBarLeft({
 /** Ahead/Behind commit status badges */
 function GitAheadBehindBadges({
   gitStatus,
+  baseBranch,
 }: {
-  gitStatus: { ahead: number; behind: number; remote_branch?: string | null };
+  gitStatus: { ahead: number; behind: number };
+  baseBranch?: string;
 }) {
   const ahead = gitStatus?.ahead ?? 0;
   const behind = gitStatus?.behind ?? 0;
   if (ahead === 0 && behind === 0) return null;
-  const remoteBranch = gitStatus?.remote_branch || "remote";
+  const compareRef = baseBranch || "main";
   return (
     <div className="flex items-center gap-1">
       {ahead > 0 && (
@@ -268,7 +270,7 @@ function GitAheadBehindBadges({
             </span>
           </TooltipTrigger>
           <TooltipContent>
-            {ahead} commit{ahead !== 1 ? "s" : ""} ahead of {remoteBranch}
+            {ahead} commit{ahead !== 1 ? "s" : ""} ahead of {compareRef}
           </TooltipContent>
         </Tooltip>
       )}
@@ -280,7 +282,7 @@ function GitAheadBehindBadges({
             </span>
           </TooltipTrigger>
           <TooltipContent>
-            {behind} commit{behind !== 1 ? "s" : ""} behind {remoteBranch}
+            {behind} commit{behind !== 1 ? "s" : ""} behind {compareRef}
           </TooltipContent>
         </Tooltip>
       )}
@@ -302,7 +304,7 @@ function TopBarRight({
 }: {
   activeSessionId?: string | null;
   baseBranch?: string;
-  gitStatus: { ahead: number; behind: number; remote_branch?: string | null };
+  gitStatus: { ahead: number; behind: number };
   showDebugOverlay?: boolean;
   onToggleDebugOverlay?: () => void;
   isArchived?: boolean;
@@ -329,7 +331,7 @@ function TopBarRight({
           </TooltipContent>
         </Tooltip>
       )}
-      <GitAheadBehindBadges gitStatus={gitStatus} />
+      <GitAheadBehindBadges gitStatus={gitStatus} baseBranch={baseBranch} />
       <DocumentControls activeSessionId={activeSessionId ?? null} />
       {!isArchived && (
         <>