subtle compile-time error involving the jmp_buf struct, which can be
different sizes depending on what macros are defined. Since libpng and
Mozilla are not necessarily compiled at the same time (at least during
development), the only way to guarantee that their concept of jmp_buf
is consistent is to avoid using it at all in one of them; specifically,
replace libpng's default error-handler with essentially the same thing
within Mozilla. (This will likely be required in a future version of
libpng, btw.)
git-svn-id: svn://10.0.0.236/trunk@44743 18797224-902f-48f8-a5cc-f745e15eee43
