[Bug go/65798] runtime.Caller returns ok=true when return data is invalid

[ian at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65798

--- Comment #3 from ian at gcc dot gnu.org <ian at gcc dot gnu.org> ---
Author: ian
Date: Fri Apr 17 21:58:58 2015
New Revision: 222203

URL: https://gcc.gnu.org/viewcvs?rev=222203&root=gcc&view=rev
Log:
    PR go/65798
runtime: In Caller don't return ok == true if PC == 0.

GCC PR 65798 reports that this can happen in some cases.

Modified:
    branches/gcc-5-branch/libgo/runtime/go-caller.c