CMake: Check for ptsname_r() again

This was dropped in autotools as I found no use of the HAVE_PTSNAME_R
macro. Turns out it was typoed as HAVE_PTS_NAME_R. Fix the #ifdef and
add checks to CMake for it.

Closes: #833674

CMake/config.h.in

@@ -34,6 +34,9 @@
 #cmakedefine HAVE_SETRESUID
 #cmakedefine HAVE_SETRESGID
 
+/* Check for ptsname_r() */
+#cmakedefine HAVE_PTSNAME_R
+
 /* Define the arch name string */
 #define COMMON_ARCH "${COMMON_ARCH}"
 

CMakeLists.txt

@@ -102,6 +102,7 @@ check_function_exists(getresuid HAVE_GETRESUID)
 check_function_exists(getresgid HAVE_GETRESGID)
 check_function_exists(setresuid HAVE_SETRESUID)
 check_function_exists(setresgid HAVE_SETRESGID)
+check_function_exists(ptsname_r HAVE_PTSNAME_R)
 check_function_exists(timegm HAVE_TIMEGM)
 test_big_endian(WORDS_BIGENDIAN)
 

apt-pkg/deb/dpkgpm.cc

@@ -1086,7 +1086,7 @@ void pkgDPkgPM::StartPtyMagic()						/*{{{*/
       _error->Errno("unlockpt", "Unlocking the slave of master fd %d failed!", d->master);
    else
    {
-#ifdef HAVE_PTS_NAME_R
+#ifdef HAVE_PTSNAME_R
       char slave_name[64];	// 64 is used by bionic
       if (ptsname_r(d->master, slave_name, sizeof(slave_name)) != 0)
 #else