Re: chown tests: Fix link error on mingw 10

[Bruno Haible]

> On mingw 10, I see a link error:

And another one in the lchown tests:

x86_64-w64-mingw32-gcc  -Wno-error -g -O2  -L/usr/local/mingw64/lib -o 
test-lchown.exe test-lchown.o libtests.a ../gllib/libgnu.a libtests.a 
../gllib/libgnu.a libtests.a   
/usr/lib/gcc/x86_64-w64-mingw32/11/../../../../x86_64-w64-mingw32/bin/ld: 
test-lchown.o: in function `test_lchown':
/home/bruno/testdir-all/build-mingw64/gltests/../../gltests/test-lchown.h:85: 
undefined reference to `getgid'
/usr/lib/gcc/x86_64-w64-mingw32/11/../../../../x86_64-w64-mingw32/bin/ld: 
/home/bruno/testdir-all/build-mingw64/gltests/../../gltests/test-lchown.h:156: 
undefined reference to `getgid'
/usr/lib/gcc/x86_64-w64-mingw32/11/../../../../x86_64-w64-mingw32/bin/ld: 
/home/bruno/testdir-all/build-mingw64/gltests/../../gltests/test-lchown.h:187: 
undefined reference to `getgid'
/usr/lib/gcc/x86_64-w64-mingw32/11/../../../../x86_64-w64-mingw32/bin/ld: 
/home/bruno/testdir-all/build-mingw64/gltests/../../gltests/test-lchown.h:204: 
undefined reference to `getgid'
collect2: error: ld returned 1 exit status
make[4]: *** [Makefile:18363: test-lchown.exe] Error 1

Extending the previous patch fixes it:


2023-04-19  Bruno Haible  <bruno@clisp.org>

        chown, lchown tests: Fix link error on mingw 10.
        * modules/chown-tests (configure.ac): Test whether getgid() exists.
        * modules/lchown-tests (configure.ac): Likewise.
        * modules/fchownat-tests (configure.ac): Likewise.
        * tests/test-chown.h (getgid): Define a fallback.
        * tests/test-lchown.h (getgid): Likewise.

diff --git a/modules/lchown-tests b/modules/lchown-tests
index 10119f22eb..2954701eeb 100644
--- a/modules/lchown-tests
+++ b/modules/lchown-tests
@@ -16,7 +16,7 @@ stdbool
 symlink
 
 configure.ac:
-AC_CHECK_FUNCS_ONCE([getegid])
+AC_CHECK_FUNCS_ONCE([getgid getegid])
 
 Makefile.am:
 TESTS += test-lchown
diff --git a/tests/test-lchown.h b/tests/test-lchown.h
index 1c68f4a1ba..3f5d0bc54c 100644
--- a/tests/test-lchown.h
+++ b/tests/test-lchown.h
@@ -18,6 +18,10 @@
 
 #include "nap.h"
 
+#if !HAVE_GETGID
+# define getgid() ((gid_t) -1)
+#endif
+
 #if !HAVE_GETEGID
 # define getegid() ((gid_t) -1)
 #endif