diff options
| -rw-r--r-- | converter/other/pnmtopng.c | 43 | ||||
| -rw-r--r-- | doc/HISTORY | 7 |
2 files changed, 35 insertions, 15 deletions
diff --git a/converter/other/pnmtopng.c b/converter/other/pnmtopng.c index 200cca44..f7be6aa0 100644 --- a/converter/other/pnmtopng.c +++ b/converter/other/pnmtopng.c @@ -2846,23 +2846,36 @@ displayVersion() { fprintf(stderr,"Pnmtopng version %s.\n", NETPBM_VERSION); - /* We'd like to display the version of libpng with which we're - linked, as we do for zlib, but it isn't practical. - While libpng is capable of telling you what it's level - is, different versions of it do it two different ways: with - png_libpng_ver or with png_get_header_ver. So we have to be - compiled for a particular version just to find out what - version it is! It's not worth having a link failure, much - less a compile failure, if we choose wrong. - png_get_header_ver is not in anything older than libpng 1.0.2a - (Dec 1998). png_libpng_ver is not there in libraries built - without USE_GLOBAL_ARRAYS. Cygwin versions are normally built - without USE_GLOBAL_ARRAYS. -bjh 2002.06.17. + /* We'd like to display the version of libpng with which we're _linked_ as + well as the one with which we're compiled, but it isn't practical. + While libpng is capable of telling you what it's level is, different + versions of it do it two different ways: with png_libpng_ver or with + png_get_header_ver. So we have to be compiled for a particular version + just to find out what version it is! It's not worth having a link + failure, much less a compile failure, if we choose wrong. + png_get_header_ver is not in anything older than libpng 1.0.2a (Dec + 1998). png_libpng_ver is not there in libraries built without + USE_GLOBAL_ARRAYS. Cygwin versions are normally built without + USE_GLOBAL_ARRAYS. -bjh 2002.06.17. + + We'd also like to display the version of libz with which we're linked, + with zlib_version (which nowadays is a macro for zlibVersion), but we + can't for reasons of modularity: We don't really link libz. libpng + does. It's none of our business whether libz is even present. And at + least on Mac OS X, we can't access libz's symbols from here -- we get + undefined reference to zlibVersion. We would have to explicitly link + libz just to find out its version. The right way to do this is for a + subroutine in libpng to give us the information. Until 10.07.08, we + did display zlib_version, but for years Mac OS X build was failing (and + we erroneously thought it was a libpng-config --ldflags bug). + + We _do_ use the compile-time part of libpng (<png.h>), because it's + part of the interface to libpng. */ - fprintf(stderr, " Compiled with libpng %s.\n", + fprintf(stderr, " Pnmtopng Compiled with libpng %s.\n", PNG_LIBPNG_VER_STRING); - fprintf(stderr, " Compiled with zlib %s; using zlib %s.\n", - ZLIB_VERSION, zlib_version); + fprintf(stderr, " Pnmtopng (not libpng) compiled with zlib %s.\n", + ZLIB_VERSION); fprintf(stderr, "\n"); } diff --git a/doc/HISTORY b/doc/HISTORY index 744f2429..63ae3cd2 100644 --- a/doc/HISTORY +++ b/doc/HISTORY @@ -6,6 +6,13 @@ CHANGE HISTORY not yet BJH Release 10.52.00 + Pnmtopng: -libversion doesn't report level of linked libz. + It was a modularity violation and caused build failures on + Mac OS X, because Pnmtopng per se doesn't know about libz -- + it's used by libpng. + + Build: don't fail due to SIGRTMIN, SIGRTMAX being undefined. + 10.06.27 BJH Release 10.51.00 Add ppmtoascii. Thanks "Frank Ch. Eigler" <fche@elastic.org>. |