show upstream branch for branch

pkg/commands/git.go

@@ -530,6 +530,11 @@ func (c *GitCommand) GetBranchGraph(branchName string) (string, error) {
 	return c.OSCommand.RunCommandWithOutput(fmt.Sprintf("git log --graph --color --abbrev-commit --decorate --date=relative --pretty=medium -100 %s", branchName))
 }
 
+func (c *GitCommand) GetUpstreamForBranch(branchName string) (string, error) {
+	output, err := c.OSCommand.RunCommandWithOutput(fmt.Sprintf("git rev-parse --abbrev-ref --symbolic-full-name %s@{u}", branchName))
+	return strings.TrimSpace(output), err
+}
+
 // Ignore adds a file to the gitignore for the repo
 func (c *GitCommand) Ignore(filename string) error {
 	return c.OSCommand.AppendLineToFile(".gitignore", filename)

pkg/gui/branches_panel.go

@@ -4,8 +4,10 @@ import (
 	"fmt"
 	"strings"
 
+	"github.com/fatih/color"
 	"github.com/jesseduffield/gocui"
 	"github.com/jesseduffield/lazygit/pkg/commands"
+	"github.com/jesseduffield/lazygit/pkg/utils"
 )
 
 // list panel functions
@@ -53,11 +55,15 @@ func (gui *Gui) handleBranchSelect(g *gocui.Gui, v *gocui.View) error {
 		_ = gui.RenderSelectedBranchUpstreamDifferences()
 	}()
 	go func() {
+		upstream, _ := gui.GitCommand.GetUpstreamForBranch(branch.Name)
+		if strings.Contains(upstream, "no upstream configured for branch") {
+			upstream = gui.Tr.SLocalize("notTrackingRemote")
+		}
 		graph, err := gui.GitCommand.GetBranchGraph(branch.Name)
 		if err != nil && strings.HasPrefix(graph, "fatal: ambiguous argument") {
 			graph = gui.Tr.SLocalize("NoTrackingThisBranch")
 		}
-		_ = gui.renderString(g, "main", graph)
+		_ = gui.renderString(g, "main", fmt.Sprintf("%s → %s\n\n%s", utils.ColoredString(branch.Name, color.FgGreen), utils.ColoredString(upstream, color.FgRed), graph))
 	}()
 	return nil
 }

pkg/i18n/english.go

@@ -840,6 +840,9 @@ func addEnglish(i18nObject *i18n.Bundle) error {
 		}, &i18n.Message{
 			ID:    "EnterUpstreamWithSlash",
 			Other: `Enter upstream as '<remote>/<branchname>'`,
+		}, &i18n.Message{
+			ID:    "notTrackingRemote",
+			Other: "(not tracking any remote)",
 		},
 	)
 }