[Freeciv-Dev] Re: (PR#12730) packets code has memory problems

["Jason Short" <jdorje@xxxxxxxxxxxxxxxxxxxxx>]

<URL: http://bugs.freeciv.org/Ticket/Display.html?id=12730 >

Per I. Mathisen wrote:
> <URL: http://bugs.freeciv.org/Ticket/Display.html?id=12730 >
> 
> Valgrind sayz:
> 
> ==18666== Conditional jump or move depends on uninitialised value(s)
> ==18666==    at 0xB7918B: (within /usr/lib/libz.so.1.2.1.2)
> ==18666==    by 0xB7A061: (within /usr/lib/libz.so.1.2.1.2)
> ==18666==    by 0xB78505: deflate (in /usr/lib/libz.so.1.2.1.2)
> ==18666==    by 0xB7681A: compress2 (in /usr/lib/libz.so.1.2.1.2)
> ==18666==    by 0x80B254D: send_packet_data (packets.c:165)
> ==18666==    by 0x80B42FB: send_packet_thaw_hint (packets_gen.c:981)
> ==18666==    by 0x80B43A9: lsend_packet_thaw_hint (packets_gen.c:1044)
> ==18666==    by 0x8084170: send_rulesets (ruleset.c:3187)
> 
> ==18662== Conditional jump or move depends on uninitialised value(s)
> ==18662==    at 0xB791D4: (within /usr/lib/libz.so.1.2.1.2)
> ==18662==    by 0xB7A061: (within /usr/lib/libz.so.1.2.1.2)
> ==18662==    by 0xB78505: deflate (in /usr/lib/libz.so.1.2.1.2)
> ==18662==    by 0xB7681A: compress2 (in /usr/lib/libz.so.1.2.1.2)
> ==18662==    by 0x80C2DFD: send_packet_data (packets.c:165)
> ==18662==    by 0x80C4BAB: send_packet_thaw_hint (packets_gen.c:981)
> ==18662==    by 0x80C4C59: lsend_packet_thaw_hint (packets_gen.c:1044)
> ==18662==    by 0x805171A: main_loop (srv_main.c:1562)

This happens when sending unitialized data over the network.  In the old 
network code you'd get "write() call contains uninitialized data", but 
now that it's passed to compress first you get a warning within that 
library.

Fixing it is trivial but tracking it down is hard.

-jason