Rewrite fuzzers to native Go harnesses (#22313)

Gitea emoji dataset was out of date because it gets manually built and
hasn't been rebuilt since it was added. This means Gitea doesn't
recognize some newer emoji or changes to existing ones.

After changing the max unicode version to 14 I just ran: `go run
build/generate-emoji.go`

This should address the initial issue seen in #22153 where Gitea doesn't
recognize a standard alias used elsewhere when importing content.

14 is the latest supported version from the upstream source as 15 is not
widely supported (in their opinion) yet

build/generate-emoji.go

@@ -25,7 +25,7 @@ import (
 
 const (
 	gemojiURL         = "https://raw.githubusercontent.com/github/gemoji/master/db/emoji.json"
-	maxUnicodeVersion = 12
+	maxUnicodeVersion = 14
 )
 
 var flagOut = flag.String("o", "modules/emoji/emoji_data.go", "out")

models/system/setting.go

@@ -275,7 +275,7 @@ func Init() error {
 		}
 	}
 
-	if enableFederatedAvatarSetting.GetValueBool() {
+	if GravatarSourceURL != nil && enableFederatedAvatarSetting.GetValueBool() {
 		LibravatarService = libravatar.New()
 		if GravatarSourceURL.Scheme == "https" {
 			LibravatarService.SetUseHTTPS(true)

tools/fuzz.go

@@ -1,50 +0,0 @@
-// Copyright 2020 The Gitea Authors. All rights reserved.
-// SPDX-License-Identifier: MIT
-
-//go:build gofuzz
-
-package fuzz
-
-import (
-	"bytes"
-	"context"
-	"io"
-
-	"code.gitea.io/gitea/modules/markup"
-	"code.gitea.io/gitea/modules/markup/markdown"
-	"code.gitea.io/gitea/modules/setting"
-)
-
-// Contains fuzzing functions executed by
-// fuzzing engine https://github.com/dvyukov/go-fuzz
-//
-// The function must return 1 if the fuzzer should increase priority of the given input during subsequent fuzzing
-// (for example, the input is lexically correct and was parsed successfully).
-// -1 if the input must not be added to corpus even if gives new coverage and 0 otherwise.
-
-var renderContext = markup.RenderContext{
-	Ctx:       context.Background(),
-	URLPrefix: "https://example.com/go-gitea/gitea",
-	Metas: map[string]string{
-		"user": "go-gitea",
-		"repo": "gitea",
-	},
-}
-
-func FuzzMarkdownRenderRaw(data []byte) int {
-	setting.AppURL = "http://localhost:3000/"
-	err := markdown.RenderRaw(&renderContext, bytes.NewReader(data), io.Discard)
-	if err != nil {
-		return 0
-	}
-	return 1
-}
-
-func FuzzMarkupPostProcess(data []byte) int {
-	setting.AppURL = "http://localhost:3000/"
-	err := markup.PostProcess(&renderContext, bytes.NewReader(data), io.Discard)
-	if err != nil {
-		return 0
-	}
-	return 1
-}

tools/fuzz_test.go

@@ -0,0 +1,38 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package main
+
+import (
+	"bytes"
+	"context"
+	"io"
+	"testing"
+
+	"code.gitea.io/gitea/modules/markup"
+	"code.gitea.io/gitea/modules/markup/markdown"
+	"code.gitea.io/gitea/modules/setting"
+)
+
+var renderContext = markup.RenderContext{
+	Ctx:       context.Background(),
+	URLPrefix: "https://example.com/go-gitea/gitea",
+	Metas: map[string]string{
+		"user": "go-gitea",
+		"repo": "gitea",
+	},
+}
+
+func FuzzMarkdownRenderRaw(f *testing.F) {
+	f.Fuzz(func(t *testing.T, data []byte) {
+		setting.AppURL = "http://localhost:3000/"
+		markdown.RenderRaw(&renderContext, bytes.NewReader(data), io.Discard)
+	})
+}
+
+func FuzzMarkupPostProcess(f *testing.F) {
+	f.Fuzz(func(t *testing.T, data []byte) {
+		setting.AppURL = "http://localhost:3000/"
+		markup.PostProcess(&renderContext, bytes.NewReader(data), io.Discard)
+	})
+}