From 1ded3fc52f7148bbb0b36cf9bdc056ca469dbce7 Mon Sep 17 00:00:00 2001
From: ZmnSCPxj jxPCSnmZ <zmnscpxj@protonmail.com>
Date: Tue, 4 Aug 2020 15:24:42 +0800
Subject: [PATCH] lightningd/plugin.c: Add a
 `--dev-builtin-plugins-unimportant` for developers who want to mess around
 with the builtin plugins.

---
 lightningd/options.c |  4 ++++
 lightningd/plugin.c  | 24 ++++++++++++++++++++++++
 lightningd/plugin.h  |  5 +++++
 tests/test_plugin.py |  6 ++++++
 4 files changed, 39 insertions(+)

diff --git a/lightningd/options.c b/lightningd/options.c
index ba0099dd7..a1dad4f22 100644
--- a/lightningd/options.c
+++ b/lightningd/options.c
@@ -566,6 +566,10 @@ static void dev_register_opts(struct lightningd *ld)
 	opt_register_noarg("--dev-no-version-checks", opt_set_bool,
 			   &ld->dev_no_version_checks,
 			   "Skip calling subdaemons with --version on startup");
+	opt_register_early_noarg("--dev-builtin-plugins-unimportant",
+				 opt_set_bool,
+				 &ld->plugins->dev_builtin_plugins_unimportant,
+				 "Make builtin plugins unimportant so you can plugin stop them.");
 }
 #endif /* DEVELOPER */
 
diff --git a/lightningd/plugin.c b/lightningd/plugin.c
index 028ce8eb6..d117b7cef 100644
--- a/lightningd/plugin.c
+++ b/lightningd/plugin.c
@@ -57,6 +57,9 @@ struct plugins *plugins_new(const tal_t *ctx, struct log_book *log_book,
 	p->json_cmds = tal_arr(p, struct command *, 0);
 	p->blacklist = tal_arr(p, const char *, 0);
 	p->shutdown = false;
+#if DEVELOPER
+	p->dev_builtin_plugins_unimportant = false;
+#endif /* DEVELOPER */
 	uintmap_init(&p->pending_requests);
 	memleak_add_helper(p, memleak_help_pending_requests);
 
@@ -1328,6 +1331,27 @@ void plugins_init(struct plugins *plugins)
 	plugins->default_dir = path_join(plugins, plugins->ld->config_basedir, "plugins");
 	plugins_add_default_dir(plugins);
 
+#if DEVELOPER
+	if (plugins->dev_builtin_plugins_unimportant) {
+		size_t i;
+
+		log_debug(plugins->log, "Builtin plugins now unimportant");
+
+		/* For each builtin plugin, check for a matching plugin
+		 * and make it unimportant.  */
+		for (i = 0; list_of_builtin_plugins[i]; ++i) {
+			const char *name = list_of_builtin_plugins[i];
+			struct plugin *p;
+			list_for_each(&plugins->plugins, p, list) {
+				if (plugin_paths_match(p->cmd, name)) {
+					p->important = false;
+					break;
+				}
+			}
+		}
+	}
+#endif /* DEVELOPER */
+
 	setenv("LIGHTNINGD_PLUGIN", "1", 1);
 	setenv("LIGHTNINGD_VERSION", version(), 1);
 
diff --git a/lightningd/plugin.h b/lightningd/plugin.h
index 5b4947460..1e4338f84 100644
--- a/lightningd/plugin.h
+++ b/lightningd/plugin.h
@@ -110,6 +110,11 @@ struct plugins {
 
 	/* Whether we are shutting down (`plugins_free` is called) */
 	bool shutdown;
+
+#if DEVELOPER
+	/* Whether builtin plugins should be overridden as unimportant.  */
+	bool dev_builtin_plugins_unimportant;
+#endif /* DEVELOPER */
 };
 
 /* The value of a plugin option, which can have different types.
diff --git a/tests/test_plugin.py b/tests/test_plugin.py
index 49dcd202f..a1830c9a7 100644
--- a/tests/test_plugin.py
+++ b/tests/test_plugin.py
@@ -1596,3 +1596,9 @@ def test_important_plugin(node_factory):
     # node should die as well.
     n.daemon.wait_for_log('pay: Plugin marked as important, shutting down lightningd')
     wait_for(lambda: not n.daemon.running)
+
+
+@unittest.skipIf(not DEVELOPER, "tests developer-only option.")
+def test_dev_builtin_plugins_unimportant(node_factory):
+    n = node_factory.get_node(options={"dev-builtin-plugins-unimportant": None})
+    n.rpc.plugin_stop(plugin="pay")