[LyX/master] Do not return copies of string members

[Enrico Forestieri]

On Thu, May 11, 2023 at 07:59:48PM +0200, Enrico Forestieri wrote:
> 
>On Thu, May 11, 2023 at 04:32:45PM +0200, Jean-Marc Lasgouttes wrote:
>>
>>Is this somthing special about cygwin or is our autoconf test broken?
>
>The former, I think.

Or not, maybe, see below.

>This is what I get when comparing cygwin and native windows 
>configuration:
>
>$ diff -up build-cygwin/config.h build-win32/config.h | grep -B1 STD_STRING
> /* std::string uses copy-on-write */
>-#define STD_STRING_USES_COW 1
>+/* #undef STD_STRING_USES_COW */
>
>So, cygwin is using COW in the std::string implementation...

I hacked config.h by undefining STD_STRING_USES_COW and recompiled.
LyX does not crash anymore and works fine, seemingly...

-- 
Enrico