Display deprecated warning in admin panel pages as well as in the log file (#26094) (#26154)

backport #26094 
Temporily resolve #25915
Related #25994

This PR includes #26007 's changes but have a UI to prompt administrator
about the deprecated settings as well as the log or console warning.
Then users will have enough time to notice the problem and don't have
surprise like before.

<img width="1293" alt="图片"
src="https://github.com/go-gitea/gitea/assets/81045/c33355f0-1ea7-4fb3-ad43-cd23cd15391d">

3 files changed, 38 insertions, 8 deletions

diff --git a/modules/setting/config_provider.go b/modules/setting/config_provider.go
index 86712792a7..d00164df9e 100644
--- a/modules/setting/config_provider.go
+++ b/modules/setting/config_provider.go
@@ -316,15 +316,14 @@ func mustMapSetting(rootCfg ConfigProvider, sectionName string, setting any) {
 	}
 }
 
-func deprecatedSetting(rootCfg ConfigProvider, oldSection, oldKey, newSection, newKey, version string) {
-	if rootCfg.Section(oldSection).HasKey(oldKey) {
-		log.Error("Deprecated fallback `[%s]` `%s` present. Use `[%s]` `%s` instead. This fallback will be/has been removed in %s", oldSection, oldKey, newSection, newKey, version)
-	}
-}
+// DeprecatedWarnings contains the warning message for various deprecations, including: setting option, file/folder, etc
+var DeprecatedWarnings []string
 
-func deprecatedSettingFatal(rootCfg ConfigProvider, oldSection, oldKey, newSection, newKey, version string) {
+func deprecatedSetting(rootCfg ConfigProvider, oldSection, oldKey, newSection, newKey, version string) {
 	if rootCfg.Section(oldSection).HasKey(oldKey) {
-		log.Fatal("Deprecated fallback `[%s]` `%s` present. Use `[%s]` `%s` instead. This fallback will be/has been removed in %s. Shutting down", oldSection, oldKey, newSection, newKey, version)
+		msg := fmt.Sprintf("Deprecated config option `[%s]` `%s` present. Use `[%s]` `%s` instead. This fallback will be/has been removed in %s", oldSection, oldKey, newSection, newKey, version)
+		log.Error("%v", msg)
+		DeprecatedWarnings = append(DeprecatedWarnings, msg)
 	}
 }
 
diff --git a/modules/setting/lfs.go b/modules/setting/lfs.go
index 75463ce1e5..4232b5115b 100644
--- a/modules/setting/lfs.go
+++ b/modules/setting/lfs.go
@@ -34,7 +34,14 @@ func loadLFSFrom(rootCfg ConfigProvider) error {
 	// Specifically default PATH to LFS_CONTENT_PATH
 	// DEPRECATED should not be removed because users maybe upgrade from lower version to the latest version
 	// if these are removed, the warning will not be shown
-	deprecatedSettingFatal(rootCfg, "server", "LFS_CONTENT_PATH", "lfs", "PATH", "v1.19.0")
+	deprecatedSetting(rootCfg, "server", "LFS_CONTENT_PATH", "lfs", "PATH", "v1.19.0")
+
+	if val := sec.Key("LFS_CONTENT_PATH").String(); val != "" {
+		if lfsSec == nil {
+			lfsSec = rootCfg.Section("lfs")
+		}
+		lfsSec.Key("PATH").MustString(val)
+	}
 
 	var err error
 	LFS.Storage, err = getStorage(rootCfg, "lfs", "", lfsSec)
diff --git a/modules/setting/lfs_test.go b/modules/setting/lfs_test.go
index 3313cae0eb..10c54fec0a 100644
--- a/modules/setting/lfs_test.go
+++ b/modules/setting/lfs_test.go
@@ -22,6 +22,30 @@ func Test_getStorageInheritNameSectionTypeForLFS(t *testing.T) {
 	assert.EqualValues(t, "lfs/", LFS.Storage.MinioConfig.BasePath)
 
 	iniStr = `
+[server]
+LFS_CONTENT_PATH = path_ignored
+[lfs]
+PATH = path_used
+`
+	cfg, err = NewConfigProviderFromData(iniStr)
+	assert.NoError(t, err)
+	assert.NoError(t, loadLFSFrom(cfg))
+
+	assert.EqualValues(t, "local", LFS.Storage.Type)
+	assert.Contains(t, LFS.Storage.Path, "path_used")
+
+	iniStr = `
+[server]
+LFS_CONTENT_PATH = deprecatedpath
+`
+	cfg, err = NewConfigProviderFromData(iniStr)
+	assert.NoError(t, err)
+	assert.NoError(t, loadLFSFrom(cfg))
+
+	assert.EqualValues(t, "local", LFS.Storage.Type)
+	assert.Contains(t, LFS.Storage.Path, "deprecatedpath")
+
+	iniStr = `
 [storage.lfs]
 STORAGE_TYPE = minio
 `