Re: [Emacs-diffs] master 6cd5678: Clarify compiler-pacifier in frame.c

[Eli Zaretskii]

> Cc: address@hidden
> From: Paul Eggert <address@hidden>
> Date: Tue, 27 Aug 2019 00:28:58 -0700
> 
>    5342    int geometry = XParseGeometry (SSDATA (string),
>    5343                                   &x, &y, &width, &height);
>    5344    Lisp_Object result = Qnil;
>    5345    if (geometry & XValue)
>    5346      {
>    5347        Lisp_Object element;
>    5348
>    5349        if (x >= 0 && (geometry & XNegative))
> 
> ... then GCC is giving a false alarm: x must be initialized in line 5349 if 
> (geometry & XValue) is nonzero in line 5345.

How do you know whether (geometry & XValue) is nonzero in each
relevant use case?  And how should GCC know that?