This looks like a bug to me:
On mingw,
/bin/sh ../../libtool --mode=link --tag=CXX g++ -g
-I/usr/src/install/3.2.3/include
-I/usr/local/include -I/c/Progra~1/GnuWin32/include
-L/usr/src/install/3.2.3/lib
-L/usr/local/lib -L/c/Progra~1/GnuWin32/lib -o libxsltwrapp.la
-rpath /usr/src/install/3.2.3/lib -L/usr/src/install/3.2.3/lib
-L/usr/local/lib
-L/c/Progra~1/GnuWin32/lib -version-info 5:0:5 -export-dynamic
-no-undefined
libxsltwrapp_la-init.lo libxsltwrapp_la-stylesheet.lo
../libxml/libxmlwrapp.la -lexslt
rm -fr .libs/libxsltwrapp.dll.a
g++ -shared -nostdlib
c:/mingw/bin/../lib/gcc-lib/mingw32/3.2.3/../../../dllcrt2.o
c:/mingw/bin/../lib/gcc-lib/mingw32/3.2.3/crtbegin.o
.libs/libxsltwrapp_la-init.o
.libs/libxsltwrapp_la-stylesheet.o -LC:/msys/1.0/local/lib
-L/usr/src/install/3.2.3/lib
-L/usr/local/lib -L/c/Progra~1/GnuWin32/lib
../libxml/.libs/libxmlwrapp.dll.a -lexslt
-Lc:/mingw/bin/../lib/gcc-lib/mingw32/3.2.3
-Lc:/mingw/bin/../lib/gcc-lib
-L/mingw/lib/gcc-lib/mingw32/3.2.3
-Lc:/mingw/bin/../lib/gcc-lib/mingw32/3.2.3/../../../../mingw32/lib
-L/mingw/lib/gcc-lib/mingw32/3.2.3/../../../../mingw32/lib
-Lc:/mingw/bin/../lib/gcc-lib/mingw32/3.2.3/../../..
-L/mingw/lib/gcc-lib/mingw32/3.2.3/../../.. -lstdc++ -lmingw32 -lgcc
-lmoldname
-lmingwex -lmsvcrt -luser32 -lkernel32 -ladvapi32 -lshell32
-lmingw32 -lgcc
-lmoldname -lmingwex -lmsvcrt
c:/mingw/bin/../lib/gcc-lib/mingw32/3.2.3/crtend.o
-o .libs/libxsltwrapp-0.dll -Wl,--image-base=0x10000000
-Wl,--out-implib,.libs/libxsltwrapp.dll.a
which results on undefined references because -lxslt is missing.
I think that -lxslt should be there because it is in
../libxml/libxmlwrapp.la:
dependency_libs=' -L/usr/src/install/3.2.3/lib -L/usr/local/lib
-L/c/Progra~1/GnuWin32/lib -LC:/msys/1.0/local/lib -lxslt -lxml2 -lz
-lm'
Why does libtool not add the dependency_libs of a linked .la to
the parameters of the g++ command?