[libpng16] build: Rename a private function to benefit C++Builder
Embarcadero's compilers, old (Borland-based) and new (Clang-based),
do have full support for Standard C. The Clang-based compiler is
claiming, through the macro __STDC_VERSION__, to support C99 and C11,
whereas the Borland-based compiler supports ANSI C, as it has for
decades.
However, their run-time library is exposing global functions beyond
the scope of Standard C, for backwards compatibility with the older
Borland products. One of these functions is `randomize`, which clashes
with a function inside pngvalid.c that incidentally has the same name.
Building libpng in "Strict ANSI C" mode, in which all Borland-specific
globals are hidden (e.g. via `bcc32 -A`), would have been a workable
solution for the Borland-based ANSI C compiler, but no such solution
appears to exist for the Clang-based C90/C99/C11 compiler.
Fortunately, renaming a private function inside a test program is a
cost-free alternative fix.
This is a cherry-pick of commit 6184164aa73ee764b1822f44d3db7619cf84f3fa
from branch 'libpng18'.
1 file changed