Ignore Sync errors on pipes when doing CheckAttributeReader.CheckPath, fix the hang of git cat-file (#17096)

* Ignore Sync errors on pipes when doing `CheckAttributeReader.CheckPath`

* apply env patch

* Drop the Sync and fix a number of issues with the Close function

Signed-off-by: Andrew Thornton <art27@cantab.net>

* add logs for DBIndexer and CheckPath

* Fix some more closing bugs

Signed-off-by: Andrew Thornton <art27@cantab.net>

* Add test case for language_stats

Signed-off-by: Andrew Thornton <art27@cantab.net>

* Update modules/indexer/stats/db.go

Co-authored-by: Lauris BH <lauris@nix.lv>

Co-authored-by: Andrew Thornton <art27@cantab.net>
Co-authored-by: Lauris BH <lauris@nix.lv>
Co-authored-by: 6543 <6543@obermui.de>

modules/git/repo_language_stats_test.go

@@ -0,0 +1,34 @@
+// Copyright 2020 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+//go:build !gogit
+// +build !gogit
+
+package git
+
+import (
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestRepository_GetLanguageStats(t *testing.T) {
+	repoPath := filepath.Join(testReposDir, "language_stats_repo")
+	gitRepo, err := OpenRepository(repoPath)
+	if !assert.NoError(t, err) {
+		t.Fatal()
+	}
+	defer gitRepo.Close()
+
+	stats, err := gitRepo.GetLanguageStats("8fee858da5796dfb37704761701bb8e800ad9ef3")
+	if !assert.NoError(t, err) {
+		t.Fatal()
+	}
+
+	assert.EqualValues(t, map[string]int64{
+		"Python": 134,
+		"Java":   112,
+	}, stats)
+}