WIP Show both ahead and behind

pkg/commands/git_commands/branch_loader.go

@@ -125,6 +125,7 @@ func (self *BranchLoader) Load(reflogCommits []*models.Commit, existingMainBranc
 			return b.Name == branch.Name
 		}); found {
 			branch.BehindBaseBranch.Store(oldBranch.BehindBaseBranch.Load())
+			branch.AheadOfBaseBranch.Store(oldBranch.AheadOfBaseBranch.Load())
 		}
 	}
 
@@ -153,12 +154,15 @@ func (self *BranchLoader) Load(reflogCommits []*models.Commit, existingMainBranc
 				if len(aheadBehindStr) != 2 {
 					return errors.New("unexpected output from git rev-list")
 				}
+				if ahead, err := strconv.Atoi(aheadBehindStr[0]); err == nil {
 					if behind, err := strconv.Atoi(aheadBehindStr[1]); err == nil {
+						branch.AheadOfBaseBranch.Store(int32(ahead))
 						branch.BehindBaseBranch.Store(int32(behind))
 						renderFunc()
 					}
 				}
 			}
+		}
 
 		return nil
 	})

pkg/commands/models/branch.go

@@ -36,6 +36,12 @@ type Branch struct {
 	// determined yet, or up to date with base branch. (We don't need to
 	// distinguish the two, as we don't draw anything in both cases.)
 	BehindBaseBranch atomic.Int32
+
+	// How far our branch is ahead of its base branch. 0 means either not
+	// determined yet, or there are no commits on this branch yet, or the branch
+	// is already merged. (We don't need to distinguish these, as we don't draw
+	// anything in all these cases.)
+	AheadOfBaseBranch atomic.Int32
 }
 
 func (b *Branch) FullRefName() string {

pkg/gui/presentation/branches.go

@@ -172,11 +172,19 @@ func BranchStatus(
 		}
 	}
 
-	if v := branch.BehindBaseBranch.Load(); v != 0 {
+	ahead := branch.AheadOfBaseBranch.Load()
+	behind := branch.BehindBaseBranch.Load()
+	if ahead != 0 || behind != 0 {
 		if result != "" {
 			result += " "
 		}
-		result += style.FgCyan.Sprintf("↓%d", v)
+		if ahead != 0 && behind != 0 {
+			result += style.FgCyan.Sprintf("↓%d↑%d", behind, ahead)
+		} else if behind != 0 {
+			result += style.FgCyan.Sprintf("↓%d", behind)
+		} else {
+			result += style.FgCyan.Sprintf("↑%d", ahead)
+		}
 	}
 
 	return result