Add restore deleted branches and their upstreams

docs-master/Config.md

@@ -777,6 +777,7 @@ keybinding:
     fetchRemote: f
     addForkRemote: F
     sortOrder: s
+    restoreBranch: <ctrl+r>
   commits:
     squashDown: s
     renameCommit: r

docs-master/keybindings/Keybindings_en.md

@@ -187,6 +187,7 @@ _This file is auto-generated. To update, make the changes in the pkg/i18n direct
 | `` - `` | Checkout previous branch |  |
 | `` F `` | Force checkout | Force checkout selected branch. This will discard all local changes in your working directory before checking out the selected branch. |
 | `` d `` | Delete | View delete options for local/remote branch. |
+| `` <ctrl+r> `` | Restore deleted branch | Restore a locally deleted branch from the reflog. The branch's upstream will be re-attached if a matching remote-tracking branch still exists. |
 | `` r `` | Rebase | Rebase the checked-out branch onto the selected branch. |
 | `` M `` | Merge | View options for merging the selected item into the current branch (regular merge, squash merge) |
 | `` f `` | Fast-forward | Fast-forward selected branch from its upstream. |

docs-master/keybindings/Keybindings_ja.md

@@ -385,6 +385,7 @@ _This file is auto-generated. To update, make the changes in the pkg/i18n direct
 | `` - `` | 直前のブランチにチェックアウト |  |
 | `` F `` | 強制チェックアウト | 選択したブランチを強制的にチェックアウトします。これにより、選択したブランチをチェックアウトする前にワーキングディレクトリ内のすべてのローカル変更が破棄されます。 |
 | `` d `` | 削除 | ローカル/リモートブランチの削除オプションを表示します。 |
+| `` <ctrl+r> `` | Restore deleted branch | Restore a locally deleted branch from the reflog. The branch's upstream will be re-attached if a matching remote-tracking branch still exists. |
 | `` r `` | リベース | チェックアウトしたブランチを選択したブランチ上にリベースします。 |
 | `` M `` | マージ | 選択した項目を現在のブランチにマージするためのオプションを表示します（通常のマージ、スカッシュマージ） |
 | `` f `` | ブランチを最新化（fast-forward） | 選択したブランチを対応するアップストリームの最新状態に追いつかせます（fast-forward）。 |

docs-master/keybindings/Keybindings_ko.md

@@ -221,6 +221,7 @@ _This file is auto-generated. To update, make the changes in the pkg/i18n direct
 | `` - `` | Checkout previous branch |  |
 | `` F `` | 강제 체크아웃 | Force checkout selected branch. This will discard all local changes in your working directory before checking out the selected branch. |
 | `` d `` | 삭제 | View delete options for local/remote branch. |
+| `` <ctrl+r> `` | Restore deleted branch | Restore a locally deleted branch from the reflog. The branch's upstream will be re-attached if a matching remote-tracking branch still exists. |
 | `` r `` | 체크아웃된 브랜치를 이 브랜치에 리베이스 | Rebase the checked-out branch onto the selected branch. |
 | `` M `` | 현재 브랜치에 병합 | View options for merging the selected item into the current branch (regular merge, squash merge) |
 | `` f `` | Fast-forward this branch from its upstream | Fast-forward selected branch from its upstream. |

docs-master/keybindings/Keybindings_nl.md

@@ -111,6 +111,7 @@ _This file is auto-generated. To update, make the changes in the pkg/i18n direct
 | `` - `` | Vorige branch uitchecken |  |
 | `` F `` | Forceer checkout | Force checkout selected branch. This will discard all local changes in your working directory before checking out the selected branch. |
 | `` d `` | Verwijderen | View delete options for local/remote branch. |
+| `` <ctrl+r> `` | Restore deleted branch | Restore a locally deleted branch from the reflog. The branch's upstream will be re-attached if a matching remote-tracking branch still exists. |
 | `` r `` | Rebase branch | Rebase de uitgecheckte branch bovenop de geselecteerde branch. |
 | `` M `` | Merge in met huidige checked out branch | View options for merging the selected item into the current branch (regular merge, squash merge) |
 | `` f `` | Fast-forward deze branch vanaf zijn upstream | Fast-forward selected branch from its upstream. |

docs-master/keybindings/Keybindings_pl.md

@@ -173,6 +173,7 @@ _This file is auto-generated. To update, make the changes in the pkg/i18n direct
 | `` - `` | Przełącz na poprzednią gałąź |  |
 | `` F `` | Wymuś przełączenie | Wymuś przełączenie wybranej gałęzi. To spowoduje odrzucenie wszystkich lokalnych zmian w drzewie roboczym przed przełączeniem na wybraną gałąź. |
 | `` d `` | Usuń | Wyświetl opcje usuwania lokalnej/odległej gałęzi. |
+| `` <ctrl+r> `` | Restore deleted branch | Restore a locally deleted branch from the reflog. The branch's upstream will be re-attached if a matching remote-tracking branch still exists. |
 | `` r `` | Przebazuj | Przebazuj przełączoną gałąź na wybraną gałąź. |
 | `` M `` | Scal | Scal wybraną gałąź z aktualnie sprawdzoną gałęzią. |
 | `` f `` | Szybkie przewijanie | Szybkie przewijanie wybranej gałęzi z jej źródła. |

docs-master/keybindings/Keybindings_pt.md

@@ -103,6 +103,7 @@ _This file is auto-generated. To update, make the changes in the pkg/i18n direct
 | `` - `` | Checkout da branch anterior |  |
 | `` F `` | Forçar checagem | Forçar checagem da branch selecionada. Isso irá descartar todas as mudanças no seu diretório de trabalho antes cheque a branch selecionada   |
 | `` d `` | Apagar | Ver opções de exclusão para a branch local/remoto. |
+| `` <ctrl+r> `` | Restore deleted branch | Restore a locally deleted branch from the reflog. The branch's upstream will be re-attached if a matching remote-tracking branch still exists. |
 | `` r `` | Refazer | Refazer a branch checada na branch selecionada |
 | `` M `` | Mesclar | Ver opções para mesclar o item selecionado no branch atual (mesclar regularmente, mesclar squash) |
 | `` f `` | Avanço rápido | Encaminhamento rápido de branch selecionada a partir do upstream. |

docs-master/keybindings/Keybindings_ru.md

@@ -221,6 +221,7 @@ _This file is auto-generated. To update, make the changes in the pkg/i18n direct
 | `` - `` | Checkout previous branch |  |
 | `` F `` | Принудительное переключение | Force checkout selected branch. This will discard all local changes in your working directory before checking out the selected branch. |
 | `` d `` | Delete | View delete options for local/remote branch. |
+| `` <ctrl+r> `` | Restore deleted branch | Restore a locally deleted branch from the reflog. The branch's upstream will be re-attached if a matching remote-tracking branch still exists. |
 | `` r `` | Перебазировать переключённую ветку на эту ветку | Rebase the checked-out branch onto the selected branch. |
 | `` M `` | Слияние с текущей переключённой веткой | View options for merging the selected item into the current branch (regular merge, squash merge) |
 | `` f `` | Перемотать эту ветку вперёд из её upstream-ветки | Fast-forward selected branch from its upstream. |

docs-master/keybindings/Keybindings_zh-CN.md

@@ -236,6 +236,7 @@ _This file is auto-generated. To update, make the changes in the pkg/i18n direct
 | `` - `` | 签出上一个分支 |  |
 | `` F `` | 强制检出 | 强制检出所选分支。这将在检出所选分支之前放弃工作目录中的所有本地更改。 |
 | `` d `` | 删除 | 查看本地/远程分支的删除选项 |
+| `` <ctrl+r> `` | Restore deleted branch | Restore a locally deleted branch from the reflog. The branch's upstream will be re-attached if a matching remote-tracking branch still exists. |
 | `` r `` | 变基 | 将检出的分支变基到所选的分支上。 |
 | `` M `` | 合并到当前检出的分支 | 查看将选中项合并到当前分支的选项(正常合并，压缩合并) |
 | `` f `` | 从上游快进此分支 | 将当前分支直接移动到远程追踪分支的最新提交 |

docs-master/keybindings/Keybindings_zh-TW.md

@@ -296,6 +296,7 @@ _This file is auto-generated. To update, make the changes in the pkg/i18n direct
 | `` - `` | Checkout previous branch |  |
 | `` F `` | 強制檢出 | Force checkout selected branch. This will discard all local changes in your working directory before checking out the selected branch. |
 | `` d `` | 刪除 | View delete options for local/remote branch. |
+| `` <ctrl+r> `` | Restore deleted branch | Restore a locally deleted branch from the reflog. The branch's upstream will be re-attached if a matching remote-tracking branch still exists. |
 | `` r `` | 將已檢出的分支變基至此分支 | Rebase the checked-out branch onto the selected branch. |
 | `` M `` | 合併到當前檢出的分支 | View options for merging the selected item into the current branch (regular merge, squash merge) |
 | `` f `` | 從上游快進此分支 | 從遠端快進所選的分支 |

pkg/commands/git_commands/branch.go

@@ -132,7 +132,47 @@ func (self *BranchCommands) PreviousRef() (string, error) {
 	return strings.TrimSpace(output), nil
 }
 
-// LocalDelete delete branch locally
+// RestoreBranch recreates a deleted local branch at the given commit hash and,
+// if exactly one remote-tracking branch with the same name still exists,
+// re-attaches it as the upstream. Returns the upstream ref name that was
+// re-attached (or "" if none was).
+func (self *BranchCommands) RestoreBranch(name string, commitHash string) (string, error) {
+	cmdArgs := NewGitCmd("branch").
+		Arg(name, commitHash).
+		ToArgv()
+
+	if err := self.cmd.New(cmdArgs).Run(); err != nil {
+		return "", err
+	}
+
+	upstream := ""
+	remoteRefs, err := self.cmd.New(
+		NewGitCmd("for-each-ref").
+			Arg("--format=%(refname:short)").
+			Arg("refs/remotes").
+			ToArgv(),
+	).DontLog().RunWithOutput()
+	if err != nil {
+		return "", err
+	}
+
+	matchingRefs := lo.Filter(strings.Split(strings.TrimSpace(remoteRefs), "\n"), func(ref string, _ int) bool {
+		return "refs/remotes/"+ref == "refs/remotes/"+name || strings.HasSuffix(ref, "/"+name)
+	})
+	if len(matchingRefs) == 1 {
+		matchingRef := strings.TrimSpace(matchingRefs[0])
+		parts := strings.SplitN(matchingRef, "/", 2)
+		if len(parts) == 2 {
+			if err := self.SetUpstream(parts[0], parts[1], name); err == nil {
+				upstream = matchingRef
+			}
+		}
+	}
+
+	return upstream, nil
+}
+
+// LocalDelete delete local branch
 func (self *BranchCommands) LocalDelete(branches []string, force bool) error {
 	cmdArgs := NewGitCmd("branch").
 		ArgIfElse(force, "-D", "-d").

pkg/commands/git_commands/branch_loader.go

@@ -490,6 +490,222 @@ func parseDifference(track string, regexStr string) string {
 	return "0"
 }
 
+// reflogEntry is a single parsed line of `git log -g` output (the reflog of
+// HEAD). Entries are fed in the order git produces them, i.e. newest first.
+type reflogEntry struct {
+	hash      string // the commit HEAD pointed at when this reflog action occurred
+	timestamp int64  // commit timestamp of the `hash` commit
+	from      string // set on "checkout: moving from X to Y" lines to the source branch X; "" otherwise
+	to        string // set to the destination branch Y on checkout lines; "" otherwise
+}
+
+// GetDeletedBranches returns branches that were deleted locally but can still
+// be restored. It infers them by walking HEAD's reflog: any branch that was
+// checked out (appears in a "checkout: moving from X to Y" line) but is no
+// longer a local branch is a candidate, and its last-known commit
+// (reconstructed from the reflog) is the commit it pointed at when it was
+// deleted.
+func (self *BranchLoader) GetDeletedBranches() ([]*models.DeletedBranch, error) {
+	existingRefs, err := self.getExistingRefNames()
+	if err != nil {
+		return nil, err
+	}
+
+	rawReflog, err := self.cmd.New(
+		NewGitCmd("log").
+			Config("log.showSignature=false").
+			Arg("-g").
+			Arg("--format=+%H%x00%ct%x00%gs").
+			ToArgv(),
+	).DontLog().RunWithOutput()
+	if err != nil {
+		return nil, err
+	}
+
+	entries := parseReflogEntries(rawReflog)
+	return obtainDeletedBranches(entries, existingRefs, self.isValidRefFormat), nil
+}
+
+// isValidRefFormat reports whether git accepts `name` as a valid ref name,
+// deferring the ref-name grammar (e.g. rejecting "HEAD~1", "main@{0}", trailing
+// dots) to `git check-ref-format`. We pass --allow-onelevel because reflog
+// checkout names are bare branch names (e.g. "master"), which are single-level
+// refs. Note that git's rules only cover shape: things like tags, remote-tracking
+// branches and abbreviated SHAs are all valid refs to git, so the caller still
+// has to filter those out separately.
+func (self *BranchLoader) isValidRefFormat(name string) bool {
+	return self.cmd.New(
+		NewGitCmd("check-ref-format").
+			Arg("--allow-onelevel").
+			Arg(name).
+			ToArgv(),
+	).DontLog().Run() == nil
+}
+
+// getExistingRefNames returns the short names of all refs (local branches,
+// remote-tracking branches and tags) plus HEAD itself. A name present here is
+// known not to be a deleted local branch, so it is excluded from recovery
+// candidates.
+func (self *BranchLoader) getExistingRefNames() ([]string, error) {
+	output, err := self.cmd.New(
+		NewGitCmd("for-each-ref").
+			Arg("--format=%(refname:short)").
+			Arg("refs/heads", "refs/remotes", "refs/tags").
+			ToArgv(),
+	).DontLog().RunWithOutput()
+	if err != nil {
+		return nil, err
+	}
+	return append(strings.Split(strings.TrimSpace(output), "\n"), "HEAD"), nil
+}
+
+// parseReflogEntries parses the raw output of
+// `git log -g --format=+%H%x00%ct%x00%gs`. The output is newest-first; we
+// preserve that order.
+func parseReflogEntries(rawReflog string) []*reflogEntry {
+	entries := make([]*reflogEntry, 0)
+	for _, line := range strings.Split(rawReflog, "\n") {
+		line = strings.TrimPrefix(line, "+")
+		if line == "" {
+			continue
+		}
+		parts := strings.SplitN(line, "\x00", 3)
+		if len(parts) != 3 {
+			continue
+		}
+		timestamp, _ := strconv.ParseInt(parts[1], 10, 64)
+		from, to := parseReflogCheckoutSubject(parts[2])
+		entries = append(entries, &reflogEntry{
+			hash:      parts[0],
+			timestamp: timestamp,
+			from:      from,
+			to:        to,
+		})
+	}
+	return entries
+}
+
+var reflogCheckoutRegex = regexp.MustCompile(`checkout: moving from ([\S]+) to ([\S]+)`)
+
+// parseReflogCheckoutSubject extracts the branch moved from and the branch
+// moved to from a "checkout: moving from X to Y" reflog subject. Returns "", ""
+// for non-checkout subjects.
+func parseReflogCheckoutSubject(subject string) (string, string) {
+	match := reflogCheckoutRegex.FindStringSubmatch(subject)
+	if len(match) != 3 {
+		return "", ""
+	}
+	return match[1], match[2]
+}
+
+// obtainDeletedBranches reconstructs deleted branches from a newest-first
+// reflog of HEAD. Returns branches that appear in the reflog as being checked
+// out but are no longer local branches, together with the commit they pointed
+// at when last seen. The result is ordered by recency (most recently committed
+// to first).
+func obtainDeletedBranches(entries []*reflogEntry, existingRefs []string, isValidRefFormat func(string) bool) []*models.DeletedBranch {
+	existing := set.NewFromSlice(existingRefs)
+
+	// currentBranch is the branch HEAD was on leading up to the current entry.
+	currentBranch := ""
+	branchTip := make(map[string]string)
+	branchTimestamp := make(map[string]int64)
+
+	for i := len(entries) - 1; i >= 0; i-- {
+		entry := entries[i]
+
+		if entry.from != "" && entry.to != "" {
+			// The hash of a checkout entry is the tip of the branch being
+			// moved to. Seeding it here means branches created via
+			// `git checkout -b` (and never committed to) are still
+			// recoverable. We never touch the source branch: its tip was
+			// recorded by the older entries that preceded this checkout, and
+			// overwriting it with the destination's tip would be wrong.
+			if isBranchName(entry.to, isValidRefFormat) {
+				branchTip[entry.to] = entry.hash
+				branchTimestamp[entry.to] = entry.timestamp
+			}
+			currentBranch = entry.to
+			continue
+		}
+
+		if currentBranch != "" && isBranchName(currentBranch, isValidRefFormat) {
+			branchTip[currentBranch] = entry.hash
+			branchTimestamp[currentBranch] = entry.timestamp
+		}
+	}
+
+	deleted := make([]*models.DeletedBranch, 0, len(branchTip))
+	for name, tip := range branchTip {
+		if existing.Includes(name) {
+			continue
+		}
+		deleted = append(deleted, &models.DeletedBranch{
+			Name:          name,
+			CommitHash:    tip,
+			Recency:       utils.UnixToTimeAgo(branchTimestamp[name]),
+			DisplayName:   name,
+			UnixTimestamp: branchTimestamp[name],
+		})
+	}
+	if len(deleted) == 0 {
+		return nil
+	}
+
+	slices.SortFunc(deleted, func(a, b *models.DeletedBranch) int {
+		if a.UnixTimestamp == b.UnixTimestamp {
+			return 0
+		}
+		if a.UnixTimestamp > b.UnixTimestamp {
+			return -1
+		}
+		return 1
+	})
+
+	return deleted
+}
+
+// isBranchName returns true if the given string could be a local branch name
+// (as opposed to a commit hash, a tag, a remote-tracking ref, or HEAD). This
+// filters out reflog noise like "checkout: moving from HEAD to abc1234" or
+// tag/remote checkouts, which would otherwise show up as phantom deleted
+// branches. The ref-name grammar itself is validated by isValidRefFormat
+// (which defers to `git check-ref-format`).
+func isBranchName(name string, isValidRefFormat func(string) bool) bool {
+	if name == "" || name == "HEAD" {
+		return false
+	}
+	if !isValidRefFormat(name) {
+		return false
+	}
+	// A name containing a slash is only treated as a branch if the part before
+	// the first slash is not a well-known remote marker (git writes
+	// "origin/feature" or "tags/v1.0" for remote/tag checkouts, and branch
+	// names can legitimately contain slashes, e.g. "feature/foo").
+	if strings.ContainsRune(name, '/') {
+		remote, _, _ := strings.Cut(name, "/")
+		return !lo.Contains([]string{"origin", "upstream", "fork", "tags", "remotes"}, remote)
+	}
+	return !looksLikeSha(name)
+}
+
+// looksLikeSha returns true if the string looks like a commit hash: all hex
+// characters and at least as long as git's minimum abbreviation. This covers
+// both abbreviated and full-length hashes that git writes for detached-head
+// checkouts. A branch name that happens to be all-hex would be missed, but
+// that's an acceptable trade-off since such names are vanishingly rare.
+func looksLikeSha(name string) bool {
+	if len(name) < 7 {
+		return false
+	}
+	for _, c := range name {
+		if !((c >= '0' && c <= '9') || (c >= 'a' && c <= 'f') || (c >= 'A' && c <= 'F')) {
+			return false
+		}
+	}
+	return true
+}
+
 // TODO: only look at the new reflog commits, and otherwise store the recencies in
 // int form against the branch to recalculate the time ago
 func (self *BranchLoader) obtainReflogBranches(reflogCommits []*models.Commit) []*models.Branch {