Update some comments and fix some warnings in main.c

src/main.c

@@ -1,4 +1,4 @@
-/* Copyright (c) 2013-2015 the Civetweb developers
+/* Copyright (c) 2013-2016 the Civetweb developers
  * Copyright (c) 2004-2013 Sergey Lyubka
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
@@ -512,7 +512,7 @@ read_config_file(const char *config_file, char **options)
 
 
 static void
-process_command_line_arguments(char *argv[], char **options)
+process_command_line_arguments(int argc, char *argv[], char **options)
 {
 	char *p;
 	size_t i, cmd_line_opts_start = 1;
@@ -521,21 +521,24 @@ process_command_line_arguments(char *argv[], char **options)
 #endif
 
 	/* Should we use a config file ? */
-	if (argv[1] != NULL && argv[1][0] != '-') {
-		/* A config file was set */
+	if ((argc > 1) && (argv[1] != NULL) && (argv[1][0] != '-')
+	    && (argv[1][0] != 0)) {
+		/* The first command line parameter is a config file name. */
 		snprintf(g_config_file_name,
 		         sizeof(g_config_file_name) - 1,
 		         "%s",
 		         argv[1]);
 		cmd_line_opts_start = 2;
 	} else if ((p = strrchr(argv[0], DIRSEP)) == NULL) {
-		/* No config file set. Use default file name in the current path. */
+		/* No config file set. No path in arg[0] found.
+		 * Use default file name in the current path. */
 		snprintf(g_config_file_name,
 		         sizeof(g_config_file_name) - 1,
 		         "%s",
 		         CONFIG_FILE);
 	} else {
-		/* No config file set. Use default file name next to the executable. */
+		/* No config file set. Path to exe found in arg[0].
+		 * Use default file name next to the executable. */
 		snprintf(g_config_file_name,
 		         sizeof(g_config_file_name) - 1,
 		         "%.*s%c%s",
@@ -838,7 +841,9 @@ start_civetweb(int argc, char *argv[])
 	char *options[2 * MAX_OPTIONS + 1];
 	int i;
 
-	/* Show system information and exit */
+	/* Start option -I:
+	 * Show system information and exit
+	 * This is very useful for diagnosis. */
 	if (argc > 1 && !strcmp(argv[1], "-I")) {
 		const char *version = mg_version();
 #if defined(_WIN32)
@@ -1052,7 +1057,7 @@ start_civetweb(int argc, char *argv[])
 	set_option(options, "document_root", ".");
 
 	/* Update config based on command line arguments */
-	process_command_line_arguments(argv, options);
+	process_command_line_arguments(argc, argv, options);
 
 	/* Make sure we have absolute paths for files and directories */
 	set_absolute_path(options, "document_root", argv[0]);
@@ -1087,14 +1092,19 @@ start_civetweb(int argc, char *argv[])
 	memset(&callbacks, 0, sizeof(callbacks));
 	callbacks.log_message = &log_message;
 	g_ctx = mg_start(&callbacks, &g_user_data, (const char **)options);
+
+	/* mg_start copies all options to an internal buffer.
+	 * The options data field here is not required anymore. */
 	for (i = 0; options[i] != NULL; i++) {
 		free(options[i]);
 	}
 
+	/* If mg_start fails, it returns NULL */
 	if (g_ctx == NULL) {
-		die("Failed to start Civetweb:\n%s",
-		    (g_user_data.first_message == NULL) ? "unknown reason"
-		                                        : g_user_data.first_message);
+		die("Failed to start %s:\n%s",
+		    g_server_name,
+		    ((g_user_data.first_message == NULL) ? "unknown reason"
+		                                         : g_user_data.first_message));
 	}
 }
 
@@ -1109,6 +1119,9 @@ stop_civetweb(void)
 
 
 #ifdef _WIN32
+/* Win32 has a small GUI.
+ * Define some GUI elements and Windows message handlers. */
+
 enum {
 	ID_ICON = 100,
 	ID_QUIT,
@@ -1140,6 +1153,7 @@ enum {
 	ID_FILE_BUTTONS_DELTA = 1000
 };
 
+
 static HICON hIcon;
 static SERVICE_STATUS ss;
 static SERVICE_STATUS_HANDLE hStatus;
@@ -1247,6 +1261,7 @@ SettingsDlgProc(HWND hDlg, UINT msg, WPARAM wParam, LPARAM lParam)
 	(void)lParam;
 
 	switch (msg) {
+
 	case WM_CLOSE:
 		DestroyWindow(hDlg);
 		break;
@@ -2147,7 +2162,7 @@ manage_service(int action)
 	char path[PATH_MAX + 20] = ""; /* Path to executable plus magic argument */
 	int success = 1;
 
-	descr.lpDescription = g_server_name;
+	descr.lpDescription = (LPSTR)g_server_name;
 
 	if ((hSCM = OpenSCManager(NULL,
 	                          NULL,
@@ -2213,10 +2228,11 @@ WindowProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
 	service_argv[1] = NULL;
 
 	memset(service_table, 0, sizeof(service_table));
-	service_table[0].lpServiceName = g_server_name;
+	service_table[0].lpServiceName = (LPSTR)g_server_name;
 	service_table[0].lpServiceProc = (LPSERVICE_MAIN_FUNCTION)ServiceMain;
 
 	switch (msg) {
+
 	case WM_CREATE:
 		if (__argv[1] != NULL && !strcmp(__argv[1], service_magic_argument)) {
 			start_civetweb(1, service_argv);
@@ -2227,6 +2243,7 @@ WindowProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
 			s_uTaskbarRestart = RegisterWindowMessage(TEXT("TaskbarCreated"));
 		}
 		break;
+
 	case WM_COMMAND:
 		switch (LOWORD(wParam)) {
 		case ID_QUIT:
@@ -2256,6 +2273,7 @@ WindowProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
 			break;
 		}
 		break;
+
 	case WM_USER:
 		switch (lParam) {
 		case WM_RBUTTONUP:
@@ -2296,12 +2314,14 @@ WindowProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
 			break;
 		}
 		break;
+
 	case WM_CLOSE:
 		stop_civetweb();
 		Shell_NotifyIcon(NIM_DELETE, &TrayIcon);
 		g_exit_flag = 1;
 		PostQuitMessage(0);
 		return 0; /* We've just sent our own quit message, with proper hwnd. */
+
 	default:
 		if (msg == s_uTaskbarRestart)
 			Shell_NotifyIcon(NIM_ADD, &TrayIcon);