Fix config file overriding environment variable

The convention for most programs is that command line options override
environment variables which in turn override config files. Removed the
test for empty as the option should be overridden unconditionally if it
exists in the environment.

In the old implementation, the host was set from the environment
variable in the first pass and then overridden by the config file in the
second pass.

NEWS

@@ -2,6 +2,7 @@ ncmpc 0.50 - not yet released
 * build: require Meson 0.56
 * lyrics/musixmatch: add new lyrics extension
 * lyrics/google: fix partial loading of lyrics
+* fix config file overriding MPD_HOST environment variable
 
 ncmpc 0.49 - (2023-08-04)
 * fix UI freeze if lyrics plugin is stuck

src/Main.cxx

@@ -301,6 +301,9 @@ try {
 	GetGlobalKeyBindings().Check(nullptr, 0);
 #endif
 
+	/* set options from environment variables */
+	options_env();
+
 	/* parse command line options - 2 pass */
 	options_parse(argc, argv);
 

src/Options.cxx

@@ -320,7 +320,11 @@ options_parse(int argc, const char *argv[])
 		handle_option(opt->shortopt, nullptr);
 	else if (opt && opt->argument)
 		option_error(ERROR_MISSING_ARGUMENT, opt->longopt, opt->argument);
+}
 
-	if (options.host.empty() && getenv("MPD_HOST"))
+void
+options_env()
+{
+	if (getenv("MPD_HOST"))
 		options.host = getenv("MPD_HOST");
 }

src/Options.hxx

@@ -97,4 +97,6 @@ extern Options options;
 
 void options_parse(int argc, const char **argv);
 
+void options_env();
+
 #endif