Remove and recreate the hooks to set them executable with the umask (#9502)

Fix #9091

models/repo.go

@@ -967,6 +967,7 @@ func CreateDelegateHooks(repoPath string) error {
 
 // createDelegateHooks creates all the hooks scripts for the repo
 func createDelegateHooks(repoPath string) (err error) {
+
 	var (
 		hookNames = []string{"pre-receive", "update", "post-receive"}
 		hookTpls  = []string{
@@ -992,10 +993,16 @@ func createDelegateHooks(repoPath string) (err error) {
 		}
 
 		// WARNING: This will override all old server-side hooks
+		if err = os.Remove(oldHookPath); err != nil && !os.IsNotExist(err) {
+			return fmt.Errorf("unable to pre-remove old hook file '%s' prior to rewriting: %v ", oldHookPath, err)
+		}
 		if err = ioutil.WriteFile(oldHookPath, []byte(hookTpls[i]), 0777); err != nil {
 			return fmt.Errorf("write old hook file '%s': %v", oldHookPath, err)
 		}
 
+		if err = os.Remove(newHookPath); err != nil && !os.IsNotExist(err) {
+			return fmt.Errorf("unable to pre-remove new hook file '%s' prior to rewriting: %v", newHookPath, err)
+		}
 		if err = ioutil.WriteFile(newHookPath, []byte(giteaHookTpls[i]), 0777); err != nil {
 			return fmt.Errorf("write new hook file '%s': %v", newHookPath, err)
 		}