add restore upstream branch menu item

Restore an upstream branch that was deleted on the remote by pushing the
local branch back to its configured upstream, removing the '(upstream gone)'
state.

pkg/gui/controllers/branches_controller.go

@@ -332,6 +332,14 @@ func (self *BranchesController) viewUpstreamOptions(selectedBranch *models.Branc
 		Keys: menuKey('s'),
 	}
 
+	restoreUpstreamItem := &types.MenuItem{
+		LabelColumns: []string{self.c.Tr.RestoreUpstreamBranch},
+		OnPress: func() error {
+			return self.pushBranchToUpstream(selectedBranch)
+		},
+		Keys: menuKey('p'),
+	}
+
 	upstreamResetOptions := utils.ResolvePlaceholderString(
 		self.c.Tr.ViewUpstreamResetOptions,
 		map[string]string{"upstream": upstream},
@@ -388,11 +396,22 @@ func (self *BranchesController) viewUpstreamOptions(selectedBranch *models.Branc
 		upstreamRebaseItem.DisabledReason = &types.DisabledReason{Text: self.c.Tr.UpstreamNotSetError}
 	}
 
+	// We can only restore an upstream that still has a tracking configuration
+	// but whose remote branch has been deleted (i.e. it shows "upstream gone").
+	if !selectedBranch.UpstreamGone {
+		disabledReason := self.c.Tr.UpstreamNotSetError
+		if selectedBranch.IsTrackingRemote() {
+			disabledReason = self.c.Tr.UpstreamNotGoneError
+		}
+		restoreUpstreamItem.DisabledReason = &types.DisabledReason{Text: disabledReason}
+	}
+
 	options := []*types.MenuItem{
 		viewDivergenceItem,
 		viewDivergenceFromBaseBranchItem,
 		unsetUpstreamItem,
 		setUpstreamItem,
+		restoreUpstreamItem,
 		upstreamResetItem,
 		upstreamRebaseItem,
 	}
@@ -754,6 +773,27 @@ func (self *BranchesController) fastForward(branch *models.Branch) error {
 	})
 }
 
+// pushBranchToUpstream pushes the given branch to its configured upstream,
+// recreating a remote branch that was deleted (e.g. on GitHub) so the branch
+// no longer shows as "upstream gone".
+func (self *BranchesController) pushBranchToUpstream(branch *models.Branch) error {
+	return self.c.WithInlineStatus(branch, types.ItemOperationPushing, context.LOCAL_BRANCHES_CONTEXT_KEY, func(task gocui.Task) error {
+		self.c.LogAction(self.c.Tr.Actions.RestoreUpstreamBranch)
+		err := self.c.Git().Sync.Push(
+			task,
+			git_commands.PushOpts{
+				CurrentBranch:  branch.Name,
+				UpstreamRemote: branch.UpstreamRemote,
+				UpstreamBranch: branch.UpstreamBranch,
+			})
+		if err != nil {
+			return err
+		}
+		self.c.RefreshFromWorker(types.RefreshOptions{Scope: []types.RefreshableView{types.BRANCHES, types.COMMITS}})
+		return nil
+	})
+}
+
 func (self *BranchesController) createTag(branch *models.Branch) error {
 	return self.c.Helpers().Tags.OpenCreateTagPrompt(branch.FullRefName(), func() {})
 }

pkg/i18n/english.go

@@ -575,6 +575,7 @@ type TranslationSet struct {
 	SetAsUpstreamTooltip                  string
 	SetUpstream                           string
 	UnsetUpstream                         string
+	RestoreUpstreamBranch                 string
 	ViewDivergenceFromUpstream            string
 	ViewDivergenceFromBaseBranch          string
 	CouldNotDetermineBaseBranch           string
@@ -646,6 +647,7 @@ type TranslationSet struct {
 	ViewBranchUpstreamOptions             string
 	ViewBranchUpstreamOptionsTooltip      string
 	UpstreamNotSetError                   string
+	UpstreamNotGoneError                  string
 	UpstreamsNotSetError                  string
 	NewGitFlowBranchPrompt                string
 	RenameBranchWarning                   string
@@ -1024,6 +1026,7 @@ type Actions struct {
 	RenameBranch                     string
 	CreateBranch                     string
 	FastForwardBranch                string
+	RestoreUpstreamBranch            string
 	AutoForwardBranches              string
 	CherryPick                       string
 	CheckoutFile                     string
@@ -1740,6 +1743,7 @@ func EnglishTranslationSet() *TranslationSet {
 		SetAsUpstreamTooltip:                 "Set the selected remote branch as the upstream of the checked-out branch.",
 		SetUpstream:                          "Set upstream of selected branch",
 		UnsetUpstream:                        "Unset upstream of selected branch",
+		RestoreUpstreamBranch:                "Restore upstream branch",
 		ViewDivergenceFromUpstream:           "View divergence from upstream",
 		ViewDivergenceFromBaseBranch:         "View divergence from base branch ({{.baseBranch}})",
 		CouldNotDetermineBaseBranch:          "Couldn't determine base branch",
@@ -1807,6 +1811,7 @@ func EnglishTranslationSet() *TranslationSet {
 		ViewBranchUpstreamOptions:        "View upstream options",
 		ViewBranchUpstreamOptionsTooltip: "View options relating to the branch's upstream e.g. setting/unsetting the upstream and resetting to the upstream.",
 		UpstreamNotSetError:              "The selected branch has no upstream (or the upstream is not stored locally)",
+		UpstreamNotGoneError:             "The selected branch's upstream still exists",
 		UpstreamsNotSetError:             "Some of the selected branches have no upstream (or the upstream is not stored locally)",
 		Upstream:                         "Upstream",
 		NewBranchNamePrompt:              "Enter new branch name for branch",
@@ -2241,6 +2246,7 @@ func EnglishTranslationSet() *TranslationSet {
 			MixedReset:                       "Mixed reset",
 			HardReset:                        "Hard reset",
 			FastForwardBranch:                "Fast forward branch",
+			RestoreUpstreamBranch:            "Restore upstream branch",
 			AutoForwardBranches:              "Auto-forward branches",
 			Undo:                             "Undo",
 			Redo:                             "Redo",

pkg/integration/components/git.go

@@ -27,6 +27,14 @@ func (self *Git) RemoteTagDeleted(ref string, tagName string) *Git {
 	})
 }
 
+// AssertRemoteBranchExists asserts that the given branch still exists on the
+// given remote, i.e. it has been pushed.
+func (self *Git) AssertRemoteBranchExists(ref string, branchName string) *Git {
+	return self.expect([]string{"git", "ls-remote", ref, fmt.Sprintf("refs/heads/%s", branchName)}, func(s string) (bool, string) {
+		return len(s) > 0, fmt.Sprintf("Expected branch %s to still exist on %s", branchName, ref)
+	})
+}
+
 func (self *Git) assert(cmdArgs []string, expected string) *Git {
 	self.expect(cmdArgs, func(output string) (bool, string) {
 		return output == expected, fmt.Sprintf("Expected current branch name to be '%s', but got '%s'", expected, output)

pkg/integration/tests/branch/restore_upstream_branch.go

@@ -0,0 +1,52 @@
+package branch
+
+import (
+	"github.com/jesseduffield/lazygit/pkg/config"
+	. "github.com/jesseduffield/lazygit/pkg/integration/components"
+)
+
+var RestoreUpstreamBranch = NewIntegrationTest(NewIntegrationTestArgs{
+	Description:  "Restore an upstream branch that was deleted on the remote",
+	ExtraCmdArgs: []string{},
+	Skip:         false,
+	SetupConfig:  func(config *config.AppConfig) {},
+	SetupRepo: func(shell *Shell) {
+		shell.
+			CloneIntoRemote("origin").
+			EmptyCommit("base commit").
+			NewBranch("feature").
+			EmptyCommit("on feature").
+			PushBranchAndSetUpstream("origin", "feature").
+			Checkout("master").
+			RunCommand([]string{"git", "-C", "../origin", "branch", "-D", "feature"}).
+			RunCommand([]string{"git", "fetch", "origin", "--prune"})
+	},
+	Run: func(t *TestDriver, keys config.KeybindingConfig) {
+		t.Views().Branches().
+			Focus().
+			Lines(
+				Contains("master").IsSelected(),
+				Contains("feature").Contains("upstream gone"),
+			)
+
+		t.Views().Branches().
+			NavigateToLine(Contains("feature")).
+			Press(keys.Branches.SetUpstream).
+			Tap(func() {
+				t.ExpectPopup().
+					Menu().
+					Title(Equals("Upstream options")).
+					Select(Contains("Restore upstream branch")).
+					Confirm()
+			})
+
+		// the "upstream gone" message is gone and the remote branch is recreated
+		t.Views().Branches().
+			Lines(
+				Contains("master"),
+				Contains("feature").DoesNotContain("upstream gone"),
+			)
+
+		t.Git().AssertRemoteBranchExists("origin", "feature")
+	},
+})

pkg/integration/tests/test_list.go

@@ -81,6 +81,7 @@ var tests = []*components.IntegrationTest{
 	branch.ResetToDuplicateNamedUpstream,
 	branch.ResetToUpstream,
 	branch.RestoreDeletedBranch,
+	branch.RestoreUpstreamBranch,
 	branch.SelectCommitsOfCurrentBranch,
 	branch.SetUpstream,
 	branch.ShowDivergenceFromBaseBranch,