zlib on mingw is misdetected

[efa]

hi,
I got an error on ./configure using MSYS2 mingw64 shell:
user@HOST MINGW64 /d/AMBIENTE/Documents/c/jbig2enc
$ ./configure
...
checking how to hardcode library paths into programs... immediate
checking for _head_libws2_32_a in -lws2_32... no
Error! zlib not detected.

where zlib is installed, complete of all headers and dll:

user@HOST MSYS /d/AMBIENTE/Documents/c/jbig2enc
$ pacman -Sl | grep zlib
mingw32 mingw-w64-i686-zlib 1.2.11-5 [installato]
mingw64 mingw-w64-x86_64-zlib 1.2.11-5 [installato]
msys mingw-w64-cross-zlib 1.2.11-1 [installato]
msys zlib 1.2.11-1 [installato]
msys zlib-devel 1.2.11-1 [installato]

user@HOST MSYS /d/AMBIENTE/Documents/c/jbig2enc
$ pacman -Ql mingw-w64-x86_64-zlib
mingw-w64-x86_64-zlib /mingw64/
mingw-w64-x86_64-zlib /mingw64/bin/
mingw-w64-x86_64-zlib /mingw64/bin/libminizip-1.dll
mingw-w64-x86_64-zlib /mingw64/bin/zlib1.dll
mingw-w64-x86_64-zlib /mingw64/include/
mingw-w64-x86_64-zlib /mingw64/include/minizip/
mingw-w64-x86_64-zlib /mingw64/include/minizip/aes/
mingw-w64-x86_64-zlib /mingw64/include/minizip/aes/aes.h
mingw-w64-x86_64-zlib /mingw64/include/minizip/aes/aes_ni.h
mingw-w64-x86_64-zlib /mingw64/include/minizip/aes/aesopt.h
mingw-w64-x86_64-zlib /mingw64/include/minizip/aes/aestab.h
mingw-w64-x86_64-zlib /mingw64/include/minizip/aes/brg_endian.h
mingw-w64-x86_64-zlib /mingw64/include/minizip/aes/brg_types.h
mingw-w64-x86_64-zlib /mingw64/include/minizip/aes/fileenc.h
mingw-w64-x86_64-zlib /mingw64/include/minizip/aes/hmac.h
mingw-w64-x86_64-zlib /mingw64/include/minizip/aes/prng.h
mingw-w64-x86_64-zlib /mingw64/include/minizip/aes/pwd2key.h
mingw-w64-x86_64-zlib /mingw64/include/minizip/aes/sha1.h
mingw-w64-x86_64-zlib /mingw64/include/minizip/crypt.h
mingw-w64-x86_64-zlib /mingw64/include/minizip/ioapi.h
mingw-w64-x86_64-zlib /mingw64/include/minizip/ioapi_buf.h
mingw-w64-x86_64-zlib /mingw64/include/minizip/ioapi_mem.h
mingw-w64-x86_64-zlib /mingw64/include/minizip/iowin32.h
mingw-w64-x86_64-zlib /mingw64/include/minizip/unzip.h
mingw-w64-x86_64-zlib /mingw64/include/minizip/zip.h
mingw-w64-x86_64-zlib /mingw64/include/zconf.h
mingw-w64-x86_64-zlib /mingw64/include/zlib.h
mingw-w64-x86_64-zlib /mingw64/lib/
mingw-w64-x86_64-zlib /mingw64/lib/cmake/
mingw-w64-x86_64-zlib /mingw64/lib/cmake/minizip-exports-release.cmake
mingw-w64-x86_64-zlib /mingw64/lib/cmake/minizip-exports.cmake
mingw-w64-x86_64-zlib /mingw64/lib/libminizip.a
mingw-w64-x86_64-zlib /mingw64/lib/libminizip.dll.a
mingw-w64-x86_64-zlib /mingw64/lib/libz.a
mingw-w64-x86_64-zlib /mingw64/lib/libz.dll.a
mingw-w64-x86_64-zlib /mingw64/lib/pkgconfig/
mingw-w64-x86_64-zlib /mingw64/lib/pkgconfig/minizip.pc
mingw-w64-x86_64-zlib /mingw64/lib/pkgconfig/zlib.pc
mingw-w64-x86_64-zlib /mingw64/share/
mingw-w64-x86_64-zlib /mingw64/share/licenses/
mingw-w64-x86_64-zlib /mingw64/share/licenses/zlib/
mingw-w64-x86_64-zlib /mingw64/share/licenses/zlib/LICENSE
mingw-w64-x86_64-zlib /mingw64/share/man/
mingw-w64-x86_64-zlib /mingw64/share/man/man3/
mingw-w64-x86_64-zlib /mingw64/share/man/man3/zlib.3.gz

As 'zlib' is present in the system and 'libws2' is not needed,
a simple dirty hack like changing lines 47/48 of 'configure.ac' to:
echo "Error! zlib not detected.")
#exit -1)
let build the binary and it work.

[efa]

attached a patch for 'configure.ac':
show WARN when winsock2 is not detected, not blame for zlib that is present and misdetected.
Generate and work on updated MSYS2.
winsock2zlib.patch.zip

[aont]

Thank you for the patch. I believe this is better.

configure.ac before

AC_CHECK_LIB(ws2_32, _head_libws2_32_a,,
	echo "Error! zlib not detected."
	exit -1)

configure.ac after

AC_CHECK_LIB(ws2_32, WSAStartup,,
	echo "Error! ws2_32 not detected."
	exit -1)

[efa]

I have no tryed on a Windows system with 2021 MSYS2 and MinGW 64 bit shell, but I suspect it will never require Winsock32.
In 2019 build and binary worked without 'libws2'
Did you try if it work?

[aont]

I tried to build without ws2_32 by commenting out ws2_32 like this.

# AC_CHECK_LIB(ws2_32, WSAStartup,,
# 	echo "Error! zlib not detected."
# 	exit -1)
# LIBS="$LIBS -lws2_32"

It ended up in error ...

libtool: link: g++ -shared -nostdlib C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/11.2.0/../../../../x86_64-w64-mingw32/lib/../lib/dllcrt2.o C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/11.2.0/crtbegin.o  .libs/jbig2enc.o .libs/jbig2arith.o .libs/jbig2sym.o .libs/jbig2comparator.o   -lz -lwebp -lgif -ljpeg -lpng -ltiff -llept -LC:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/11.2.0 -LC:/msys64/mingw64/bin/../lib/gcc -LC:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/11.2.0/../../../../x86_64-w64-mingw32/lib/../lib -LC:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/11.2.0/../../../../lib -LC:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/11.2.0/../../../../x86_64-w64-mingw32/lib -LC:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/11.2.0/../../.. -lstdc++ -lmingw32 -lgcc_s -lgcc -lmoldname -lmingwex -lmsvcrt -lkernel32 -lpthread -ladvapi32 -lshell32 -luser32 -lkernel32 -lmingw32 -lgcc_s -lgcc -lmoldname -lmingwex -lmsvcrt -lkernel32 C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/11.2.0/crtend.o  -g -O2   -o .libs/libjbig2enc-0.dll -Wl,--enable-auto-image-base -Xlinker --out-implib -Xlinker .libs/libjbig2enc.dll.a
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/11.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: .libs/jbig2enc.o: in function `jbig2_encode_generic(Pix*, bool, int, int, bool, int*)':
C:\Users\user\Downloads\jbig2enc-0.29\src/jbig2enc.cc:899: undefined reference to `__imp_htonl'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/11.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: .libs/jbig2enc.o: in function `jbig2_pages_complete(jbig2ctx*, int*)':
C:\Users\user\Downloads\jbig2enc-0.29\src/jbig2enc.cc:688: undefined reference to `__imp_htonl'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/11.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:\Users\user\Downloads\jbig2enc-0.29\src/jbig2enc.cc:666: undefined reference to `__imp_htonl'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/11.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: .libs/jbig2enc.o: in function `jbig2_produce_page(jbig2ctx*, int, int, int, int*)':
C:\Users\user\Downloads\jbig2enc-0.29\src/jbig2enc.cc:743: undefined reference to `__imp_htonl'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/11.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: .libs/jbig2enc.o: in function `Segment::write(unsigned char*)':
C:\Users\user\Downloads\jbig2enc-0.29\src/jbig2segments.h:130: undefined reference to `__imp_htonl'
C:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/11.2.0/../../../../x86_64-w64-mingw32/bin/ld.exe: C:\Users\user\Downloads\jbig2enc-0.29\src/jbig2segments.h:154: undefined reference to `__imp_htons'
collect2.exe: error: ld returned 1 exit status
make[1]: *** [Makefile:470: libjbig2enc.la] Error 1
make[1]: Leaving directory '/c/Users/user/Downloads/jbig2enc-0.29/src'
make: *** [Makefile:478: all-recursive] Error 1

ws2_32 is used for endian conversion ?

[efa]

probably 'htonl' is in the network stack