Handle push rejection in branch and upload (#10854)

* Handle push rejections and push out-of-date in branch creation and
file upload.
* Remove the duplicated sanitize from services/pull/merge
* Move the errors Err(Merge)PushOutOfDate and ErrPushRejected to
modules/git
* Handle errors better in the upload file dialogs

Fix #10460

Signed-off-by: Andrew Thornton <art27@cantab.net>
Co-authored-by: guillep2k <18600385+guillep2k@users.noreply.github.com>

modules/git/error.go

@@ -6,6 +6,7 @@ package git
 
 import (
 	"fmt"
+	"strings"
 	"time"
 )
 
@@ -85,3 +86,76 @@ func IsErrBranchNotExist(err error) bool {
 func (err ErrBranchNotExist) Error() string {
 	return fmt.Sprintf("branch does not exist [name: %s]", err.Name)
 }
+
+// ErrPushOutOfDate represents an error if merging fails due to unrelated histories
+type ErrPushOutOfDate struct {
+	StdOut string
+	StdErr string
+	Err    error
+}
+
+// IsErrPushOutOfDate checks if an error is a ErrPushOutOfDate.
+func IsErrPushOutOfDate(err error) bool {
+	_, ok := err.(*ErrPushOutOfDate)
+	return ok
+}
+
+func (err *ErrPushOutOfDate) Error() string {
+	return fmt.Sprintf("PushOutOfDate Error: %v: %s\n%s", err.Err, err.StdErr, err.StdOut)
+}
+
+// Unwrap unwraps the underlying error
+func (err *ErrPushOutOfDate) Unwrap() error {
+	return fmt.Errorf("%v - %s", err.Err, err.StdErr)
+}
+
+// ErrPushRejected represents an error if merging fails due to rejection from a hook
+type ErrPushRejected struct {
+	Message string
+	StdOut  string
+	StdErr  string
+	Err     error
+}
+
+// IsErrPushRejected checks if an error is a ErrPushRejected.
+func IsErrPushRejected(err error) bool {
+	_, ok := err.(*ErrPushRejected)
+	return ok
+}
+
+func (err *ErrPushRejected) Error() string {
+	return fmt.Sprintf("PushRejected Error: %v: %s\n%s", err.Err, err.StdErr, err.StdOut)
+}
+
+// Unwrap unwraps the underlying error
+func (err *ErrPushRejected) Unwrap() error {
+	return fmt.Errorf("%v - %s", err.Err, err.StdErr)
+}
+
+// GenerateMessage generates the remote message from the stderr
+func (err *ErrPushRejected) GenerateMessage() {
+	messageBuilder := &strings.Builder{}
+	i := strings.Index(err.StdErr, "remote: ")
+	if i < 0 {
+		err.Message = ""
+		return
+	}
+	for {
+		if len(err.StdErr) <= i+8 {
+			break
+		}
+		if err.StdErr[i:i+8] != "remote: " {
+			break
+		}
+		i += 8
+		nl := strings.IndexByte(err.StdErr[i:], '\n')
+		if nl >= 0 {
+			messageBuilder.WriteString(err.StdErr[i : i+nl+1])
+			i = i + nl + 1
+		} else {
+			messageBuilder.WriteString(err.StdErr[i:])
+			i = len(err.StdErr)
+		}
+	}
+	err.Message = strings.TrimSpace(messageBuilder.String())
+}