chore: initialize Gitea v1.27.2 fork

Includes direct password setup links in registration emails.

Assisted-by: Codex:GPT-5

modules/git/gitcmd/error.go

@@ -0,0 +1,133 @@
+// Copyright 2026 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package gitcmd
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"os/exec"
+	"strings"
+
+	"gitea.dev/modules/setting"
+	"gitea.dev/modules/util"
+)
+
+type RunStdError interface {
+	error
+	Unwrap() error
+	Stderr() string
+}
+
+type runStdError struct {
+	err    error  // usually the low-level error like `*exec.ExitError`
+	stderr string // git command's stderr output
+	errMsg string // the cached error message for Error() method
+}
+
+func (r *runStdError) Error() string {
+	// FIXME: GIT-CMD-STDERR: it is a bad design, the stderr should not be put in the error message
+	// But a lot of code only checks `strings.Contains(err.Error(), "git error")`
+	if r.errMsg == "" {
+		r.errMsg = fmt.Sprintf("%s - %s", r.err.Error(), strings.TrimSpace(r.stderr))
+	}
+	return r.errMsg
+}
+
+func (r *runStdError) Unwrap() error {
+	return r.err
+}
+
+func (r *runStdError) Stderr() string {
+	return r.stderr
+}
+
+func ErrorAsStderr(err error) (string, bool) {
+	if runErr, ok := errors.AsType[RunStdError](err); ok {
+		return runErr.Stderr(), true
+	}
+	return "", false
+}
+
+func IsErrorExitCode(err error, code int) bool {
+	if exitError, ok := errors.AsType[*exec.ExitError](err); ok {
+		return exitError.ExitCode() == code
+	}
+	return false
+}
+
+func IsErrorSignalKilled(err error) bool {
+	var exitError *exec.ExitError
+	return errors.As(err, &exitError) && exitError.String() == "signal: killed"
+}
+
+func IsErrorCanceledOrKilled(err error) bool {
+	// When "cancel()" a git command's context, the returned error of "Run()" could be one of them:
+	// - context.Canceled
+	// - *exec.ExitError: "signal: killed"
+	// TODO: in the future, we need to use unified error type from gitcmd.Run to check whether it is manually canceled
+	return errors.Is(err, context.Canceled) || IsErrorSignalKilled(err)
+}
+
+type (
+	StderrPrefix   string
+	StderrWildcard string
+)
+
+const (
+	StderrNotValidObjectName StderrPrefix = "fatal: not a valid object name"
+	StderrNotTreeObject      StderrPrefix = "fatal: not a tree object"
+	StderrPathSpec           StderrPrefix = "fatal: pathspec"
+	StderrBadRevision        StderrPrefix = "fatal: bad revision"
+
+	StderrNoSuchRemote1 StderrPrefix = "fatal: no such remote" // git < 2.30, exit status 128
+	StderrNoSuchRemote2 StderrPrefix = "error: no such remote" // git >= 2.30. exit status 2
+
+	StderrUnknownRevisionOrPath StderrWildcard = "fatal: *: unknown revision or path not in the working tree"
+	StderrNoMergeBase           StderrWildcard = "fatal: *: no merge base"
+)
+
+func IsStderr[T StderrPrefix | StderrWildcard](err error, check T) bool {
+	stderr, ok := ErrorAsStderr(err)
+	if !ok {
+		return false
+	}
+	checkLen := len(check)
+	if len(stderr) < checkLen {
+		return false
+	}
+	switch any(check).(type) {
+	case StderrPrefix:
+		// Git is lowercasing the "fatal: Not a valid object name" error message
+		// ref: https://lore.kernel.org/git/pull.2052.git.1771836302101.gitgitgadget@gmail.com
+		return util.AsciiEqualFold(stderr[:checkLen], string(check))
+	case StderrWildcard:
+		prefix, remaining, _ := strings.Cut(string(check), "*")
+		return strings.HasPrefix(stderr, prefix) && strings.Contains(stderr, remaining)
+	}
+	setting.PanicInDevOrTesting("invalid stderr type %T", check)
+	return false
+}
+
+type pipelineError struct {
+	error
+}
+
+func (e pipelineError) Unwrap() error {
+	return e.error
+}
+
+func wrapPipelineError(err error) error {
+	if err == nil {
+		return nil
+	}
+	return pipelineError{err}
+}
+
+func UnwrapPipelineError(err error) (error, bool) { //nolint:revive // this is for error unwrapping
+	if pe, ok := errors.AsType[pipelineError](err); ok {
+		return pe.error, true
+	}
+	return nil, false
+}