Allow instance-wide disabling of forking

For small, personal self-hosted instances with no user signups, the fork
button is just a noise. This patch allows disabling them like stars can
be disabled too.

Disabling forks does not only remove the buttons from the web UI, it
also disables the routes that could be used to create forks.

Fixes #2441.

Signed-off-by: Gergely Nagy <forgejo@gergo.csillger.hu>

modules/context/context.go

@@ -198,6 +198,7 @@ func Contexter() func(next http.Handler) http.Handler {
 			// FIXME: do we really always need these setting? There should be someway to have to avoid having to always set these
 			ctx.Data["DisableMigrations"] = setting.Repository.DisableMigrations
 			ctx.Data["DisableStars"] = setting.Repository.DisableStars
+			ctx.Data["DisableForks"] = setting.Repository.DisableForks
 			ctx.Data["EnableActions"] = setting.Actions.Enabled
 
 			ctx.Data["ManifestData"] = setting.ManifestData

modules/setting/repository.go

@@ -50,6 +50,7 @@ var (
 		PrefixArchiveFiles                      bool
 		DisableMigrations                       bool
 		DisableStars                            bool `ini:"DISABLE_STARS"`
+		DisableForks                            bool
 		DefaultBranch                           string
 		AllowAdoptionOfUnadoptedRepositories    bool
 		AllowDeleteOfUnadoptedRepositories      bool
@@ -172,6 +173,7 @@ var (
 		PrefixArchiveFiles:                      true,
 		DisableMigrations:                       false,
 		DisableStars:                            false,
+		DisableForks:                            false,
 		DefaultBranch:                           "main",
 		AllowForkWithoutMaximumLimit:            true,
 

modules/structs/settings.go

@@ -9,6 +9,7 @@ type GeneralRepoSettings struct {
 	HTTPGitDisabled      bool `json:"http_git_disabled"`
 	MigrationsDisabled   bool `json:"migrations_disabled"`
 	StarsDisabled        bool `json:"stars_disabled"`
+	ForksDisabled        bool `json:"forks_disabled"`
 	TimeTrackingDisabled bool `json:"time_tracking_disabled"`
 	LFSDisabled          bool `json:"lfs_disabled"`
 }