Centralize catgets() calls through MsgCat

CDE has relied upon catgets() implementations following a relaxed
interpretation of the XPG internationalization standard that ignored
-1, the standard error value returned by catopen, as the catalog
argument. However, this same behavior causes segmentation faults with
the musl C library.

This patch:

- Centralizes (with the exception of ToolTalk) all calls to catopen(),
  catgets(), and catclose() through MsgCat within the DtSvc library.
- Prevents calls to catgets() and catclose() that rely upon
  undefined behavior.
- Eliminates a number of bespoke catgets() wrappers, including multiple
  redundant caching implementations designed to work around a design
  peculiarity in HP/UX.
- Eases building CDE without XPG internationalization support by providing
  the appropriate macros.

cde/programs/dtlogin/Imakefile

@@ -166,7 +166,8 @@ INCLUDES = -I$(XPROJECTROOT)/include/freetype2
                   dpylist.o error.o file.o mitauth.o protodpy.o policy.o \
                   reset.o resource.o server.o session.o socket.o util.o \
                   verify.o sysauth.o fontpath.o $(DESOBJS) qualify.o choose.o \
-		  netaddr.o xdmcp.o $(PAM_OBJS) $(SOLARIS_OBJS)
+		  netaddr.o xdmcp.o $(PAM_OBJS) $(SOLARIS_OBJS) \
+		  $(CDELIBSRC)/DtSvc/DtUtil2/MsgCat.o
 
           PROG2 = dtgreet
 #ifdef AlphaArchitecture

cde/programs/dtlogin/chooser.c

@@ -100,10 +100,6 @@ in this Software without prior written authorization from the X Consortium.
 #include    <stdio.h>
 #include    <ctype.h>
 #include    <locale.h>
-#include    <nl_types.h>
-#ifndef NL_CAT_LOCALE
-#define NL_CAT_LOCALE 0
-#endif
 
 #ifdef SVR4
 #include    <sys/sockio.h>

cde/programs/dtlogin/util.c

@@ -58,7 +58,7 @@
 #include    <setjmp.h>
 #include    <string.h>
 #include    <dirent.h>
-#include    <nl_types.h>
+#include    <Dt/MsgCatP.h>
 
 # include   <sys/signal.h>
 
@@ -112,7 +112,6 @@ unsigned char *
 ReadCatalog( int set_num, int msg_num, char *def_str )
 {
     static Bool alreadyopen = False;
-    char *s;
 
     if (alreadyopen == False)
     {
@@ -174,12 +173,10 @@ ReadCatalog( int set_num, int msg_num, char *def_str )
       * msg catalog could not be opened), subsequent call to catgets() using
       * that descriptor will return 'def_str'.
       */
-      nl_fd = catopen("dtlogin", NL_CAT_LOCALE);
+      nl_fd = CATOPEN("dtlogin", NL_CAT_LOCALE);
     }
 
-    s = catgets(nl_fd,set_num,msg_num,def_str);
-    
-    return((unsigned char *)s);
+    return ((unsigned char *) CATGETS(nl_fd, set_num, msg_num, def_str));
 }
 
 void

cde/programs/dtlogin/vgutil.c

@@ -54,7 +54,6 @@
  *
  ***************************************************************************/
 
-#include <nl_types.h>
 #include <stdio.h>
 #include <setjmp.h>
 #include <time.h>
@@ -64,6 +63,7 @@
 
 #include <X11/Xlibint.h>
 #include <Xm/Xm.h>
+#include <Dt/MsgCatP.h>
 
 #include "vg.h"
 #include "vgmsg.h"
@@ -734,7 +734,7 @@ LogError( unsigned char *fmt, ...)
 void
 CloseCatalog(void)
 {
-    catclose(nl_fd);
+    CATCLOSE(nl_fd);
 }
 
 /***************************************************************************
@@ -773,7 +773,7 @@ OpenCatalog(void)
      */
     if (NULL != langenv)
     {
-	nl_fd = catopen(NLS_CATALOG, NL_CAT_LOCALE);
+	nl_fd = CATOPEN(NLS_CATALOG, NL_CAT_LOCALE);
 	if (0 > (long) nl_fd)
 	  LogError((unsigned char*) MC_DEF_LOG_NO_MSGCAT, langenv);
     }
@@ -794,7 +794,7 @@ ReadCatalog(int setn, int msgn, char *dflt)
     if ((0 > (long) nl_fd) || (NULL == langenv))
       return (unsigned char*) dflt;
     else
-      return (unsigned char*) catgets(nl_fd, setn, msgn, dflt);
+      return (unsigned char*) CATGETS(nl_fd, setn, msgn, dflt);
 }
  
 /***************************************************************************
@@ -1127,48 +1127,3 @@ ToPixel( Widget w, int orientation, int pixel )
 			      XmPIXELS));
     }
 }
-
-
-
-#if 0
-/***************************************************************************
- *
- *  _DtMessage Catalog Stubs
- *
- *  These stub routines can be used for porting to systems that do not yet
- *  support message catalogs. Replace the above "0" with an appropriate
- *  define for your target system. Do the same for the external defines
- *  in "vg.h".
- ***************************************************************************/
-
-nl_catd
-catopen(name, oflag)
-  char	  *name;
-  int	   oflag;
-
-{
-  return (555);
-}
-
-  
-int
-catclose(catd)
-  nl_catd  catd;
-
-{
-  return;
-}
-  
-
-char *
-catgets(catd, set_num, msg_num, def_str)
-  nl_catd  catd;
-  int	   set_num;
-  int	   msg_num;
-  char	  *def_str;
-
-{
-    return (def_str);
-}    
-
-#endif

cde/programs/dtlogin/xdm_msg.h

@@ -30,7 +30,6 @@
 #ifndef _H_XDM_MSG 
 #define _H_XDM_MSG 
 #include <limits.h>
-#include <nl_types.h>
 #define MF_XDM "xdm.cat"