manpage: updating the section about nil vs fteqcc-__NULL__

diff --git a/doc/gmqcc.1 b/doc/gmqcc.1
index 940afd0fa04919ccd81054ec782ee0d7ae66d5c1..2a38e2a9de7f644215365a99480b3431748a72b0 100644 (file)
--- a/doc/gmqcc.1
+++ b/doc/gmqcc.1
@@ -448,13 +448,18 @@ anything. No typechecking will be performed on assignments. Assigning
 to it is forbidden, using it in any other kind of expression is also
 not allowed.
 .sp
 to it is forbidden, using it in any other kind of expression is also
 not allowed.
 .sp

-Note that this is different from fteqcc's __NULL__ in that gmqcc
-generates an actual empty global, rather than using the global at
-offset 0 because it would overlap with the global RETURN variable when
-dealing with vectors, which starts at offset 1. Setting a vector to
-__NULL__ in fteqcc causes only the vector's x component to be 0.
-However, its y and z components will contain the previous x and y
-components of the global OFS_RETURN.
+Note that this is different from fteqcc's __NULL__: In fteqcc,
+__NULL__ maps to the integer written as '0i'. It's can be assigned to
+function pointers and integers, but it'll error about invalid
+instructions when assigning it to floats without enabling the FTE
+instruction set. There's also a bug which allows it to be assigned to
+vectors, for which the source will be the global at offset 0, meaning
+the vector's y and z components will contain the OFS_RETURN x and y
+components.
+.sp
+In that gmqcc the nil global is an actual global filled with zeroes,
+and can be assigned to anything including fields, vectors or function
+pointers, and they end up becoming zeroed.

 .TP
 .B -fpermissive
 Various effects, usually to weaken some conditions.
 .TP
 .B -fpermissive
 Various effects, usually to weaken some conditions.