UI: Don't subject base/output resolutions defaults

If defaults change for the base or output resolutions, it could
unintentionally affect users who are using defaults by chance and have
never changed those values.

Instead, save those values are soon as defaults are set if the users
haven't already set them.

UI/window-basic-main.cpp

@@ -996,6 +996,14 @@ bool OBSBasic::InitBasicConfigDefaults()
 	config_set_default_uint  (basicConfig, "Video", "BaseCX",   cx);
 	config_set_default_uint  (basicConfig, "Video", "BaseCY",   cy);
 
+	/* don't allow BaseCX/BaseCY to be susceptible to defaults changing */
+	if (!config_has_user_value(basicConfig, "Video", "BaseCX") ||
+	    !config_has_user_value(basicConfig, "Video", "BaseCY")) {
+		config_set_uint(basicConfig, "Video", "BaseCX", cx);
+		config_set_uint(basicConfig, "Video", "BaseCY", cy);
+		config_save_safe(basicConfig, "tmp", nullptr);
+	}
+
 	config_set_default_string(basicConfig, "Output", "FilenameFormatting",
 			"%CCYY-%MM-%DD %hh-%mm-%ss");
 
@@ -1028,6 +1036,15 @@ bool OBSBasic::InitBasicConfigDefaults()
 	config_set_default_uint  (basicConfig, "Video", "OutputCX", scale_cx);
 	config_set_default_uint  (basicConfig, "Video", "OutputCY", scale_cy);
 
+	/* don't allow OutputCX/OutputCY to be susceptible to defaults
+	 * changing */
+	if (!config_has_user_value(basicConfig, "Video", "OutputCX") ||
+	    !config_has_user_value(basicConfig, "Video", "OutputCY")) {
+		config_set_uint(basicConfig, "Video", "OutputCX", scale_cx);
+		config_set_uint(basicConfig, "Video", "OutputCY", scale_cy);
+		config_save_safe(basicConfig, "tmp", nullptr);
+	}
+
 	config_set_default_uint  (basicConfig, "Video", "FPSType", 0);
 	config_set_default_string(basicConfig, "Video", "FPSCommon", "30");
 	config_set_default_uint  (basicConfig, "Video", "FPSInt", 30);