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Fix numoflines calculations in sectorlines_* functions by first typecasting seclines (the sector.lines address) to size_t before doing any math on it, then (after the math) typecast the result to size_t * and dereference it.

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And yes, this time I tested it to make sure it works :)
This commit is contained in:
Monster Iestyn 2019-12-16 17:46:27 +00:00
parent 130794cc4d
commit f028bb0219
1 changed files with 2 additions and 2 deletions
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4
src/lua_maplib.c
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@ -445,7 +445,7 @@ static int sectorlines_get(lua_State *L)
// get the "linecount" by shifting our retrieved memory address of "lines" to where "linecount" is in the sector_t, then dereferencing the result // get the "linecount" by shifting our retrieved memory address of "lines" to where "linecount" is in the sector_t, then dereferencing the result
// we need this to determine the array's actual size, and therefore also the maximum value allowed as an index // we need this to determine the array's actual size, and therefore also the maximum value allowed as an index
// this only works if seclines is actually a pointer to a sector's lines member in memory, oh boy // this only works if seclines is actually a pointer to a sector's lines member in memory, oh boy
numoflines = (size_t)(*(seclines - (offsetof(sector_t, lines) - offsetof(sector_t, linecount)))); numoflines = (size_t)(*(size_t *)(((size_t)seclines) - (offsetof(sector_t, lines) - offsetof(sector_t, linecount))));
/* OLD HACK /* OLD HACK
// check first linedef to figure which of its sectors owns this sector->lines pointer // check first linedef to figure which of its sectors owns this sector->lines pointer
@ -479,7 +479,7 @@ static int sectorlines_num(lua_State *L)
return luaL_error(L, "accessed sector_t.lines doesn't exist anymore."); return luaL_error(L, "accessed sector_t.lines doesn't exist anymore.");
// see comments in the _get function above // see comments in the _get function above
numoflines = (size_t)(*(seclines - (offsetof(sector_t, lines) - offsetof(sector_t, linecount)))); numoflines = (size_t)(*(size_t *)(((size_t)seclines) - (offsetof(sector_t, lines) - offsetof(sector_t, linecount))));
lua_pushinteger(L, numoflines); lua_pushinteger(L, numoflines);
return 1; return 1;
} }