refactor: decouple early return commands from AppInit

Cleaned up the init flow to make it more obvious when
the 'exit_status' value will and won't be returned.

This is because it was confusing that `AppInit` was
returning true under two different circumstances:

1) When bitcoind was launched only to retrieve the "-help"
or "-version" information. In this case, the app was
not initialized.

2) When the user triggers a shutdown. In this case,
the app was fully initialized.

Author: furszy

src/bitcoind.cpp

@@ -112,20 +112,30 @@ int fork_daemon(bool nochdir, bool noclose, TokenPipeEnd& endpoint)
 
 #endif
 
-static bool AppInit(NodeContext& node, int argc, char* argv[])
+static bool ParseArgs(ArgsManager& args, int argc, char* argv[])
 {
-    bool fRet = false;
-
-    util::ThreadSetInternalName("init");
-
     // If Qt is used, parameters/bitcoin.conf are parsed in qt/bitcoin.cpp's main()
-    ArgsManager& args = *Assert(node.args);
     SetupServerArgs(args);
     std::string error;
     if (!args.ParseParameters(argc, argv, error)) {
         return InitError(Untranslated(strprintf("Error parsing command line arguments: %s", error)));
     }
 
+    if (auto error = common::InitConfig(args)) {
+        return InitError(error->message, error->details);
+    }
+
+    // Error out when loose non-argument tokens are encountered on command line
+    for (int i = 1; i < argc; i++) {
+        if (!IsSwitchChar(argv[i][0])) {
+            return InitError(Untranslated(strprintf("Command line contains unexpected token '%s', see bitcoind -h for a list of options.", argv[i])));
+        }
+    }
+    return true;
+}
+
+static bool ProcessInitCommands(ArgsManager& args)
+{
     // Process help and version before taking care about datadir
     if (HelpRequested(args) || args.IsArgSet("-version")) {
         std::string strUsage = PACKAGE_NAME " version " + FormatFullVersion() + "\n";
@@ -142,6 +152,14 @@ static bool AppInit(NodeContext& node, int argc, char* argv[])
         return true;
     }
 
+    return false;
+}
+
+static bool AppInit(NodeContext& node)
+{
+    bool fRet = false;
+    ArgsManager& args = *Assert(node.args);
+
 #if HAVE_DECL_FORK
     // Communication with parent after daemonizing. This is used for signalling in the following ways:
     // - a boolean token is sent when the initialization process (all the Init* functions) have finished to indicate
@@ -153,17 +171,6 @@ static bool AppInit(NodeContext& node, int argc, char* argv[])
     std::any context{&node};
     try
     {
-        if (auto error = common::InitConfig(args)) {
-            return InitError(error->message, error->details);
-        }
-
-        // Error out when loose non-argument tokens are encountered on command line
-        for (int i = 1; i < argc; i++) {
-            if (!IsSwitchChar(argv[i][0])) {
-                return InitError(Untranslated(strprintf("Command line contains unexpected token '%s', see bitcoind -h for a list of options.", argv[i])));
-            }
-        }
-
         // -server defaults to true for bitcoind but not for the GUI so do this here
         args.SoftSetBoolArg("-server", true);
         // Set this early so that parameter interactions go to console
@@ -236,14 +243,6 @@ static bool AppInit(NodeContext& node, int argc, char* argv[])
     }
 #endif
     SetSyscallSandboxPolicy(SyscallSandboxPolicy::SHUTOFF);
-    if (fRet) {
-        WaitForShutdown();
-    } else {
-        node.exit_status = EXIT_FAILURE;
-    }
-    Interrupt(node);
-    Shutdown(node);
-
     return fRet;
 }
 
@@ -266,5 +265,22 @@ MAIN_FUNCTION
     // Connect bitcoind signal handlers
     noui_connect();
 
-    return AppInit(node, argc, argv) ? node.exit_status.load() : EXIT_FAILURE;
+    util::ThreadSetInternalName("init");
+
+    // Interpret command line arguments
+    ArgsManager& args = *Assert(node.args);
+    if (!ParseArgs(args, argc, argv)) return EXIT_FAILURE;
+    // Process early info return commands such as -help or -version
+    if (ProcessInitCommands(args)) return EXIT_SUCCESS;
+
+    // Start application
+    if (AppInit(node)) {
+        WaitForShutdown();
+    } else {
+        node.exit_status = EXIT_FAILURE;
+    }
+    Interrupt(node);
+    Shutdown(node);
+
+    return node.exit_status;
 }