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/lib/DtHelp/FormatMan.c

@@ -53,7 +53,6 @@
 #endif
 #include <limits.h>
 #include <locale.h>
-#include <nl_types.h>
 #include <string.h>
 #include <unistd.h>
 #include <stdio.h>

cde/lib/DtHelp/FormatUtil.c

@@ -75,7 +75,7 @@ extern int errno;
 #include "FormatUtilI.h"
 
 #if defined(NLS16) || !defined(NO_MESSAGE_CATALOG)
-#include <nl_types.h>
+#include <Dt/MsgCatP.h>
 #endif
 
 #ifndef NL_CAT_LOCALE
@@ -789,13 +789,13 @@ _DtHelpLoadMultiInfo (
     char     *ptr;
     nl_catd   cat_fd;
 
-    cat_fd = catopen ("fmt_tbl", NL_CAT_LOCALE);
+    cat_fd = CATOPEN("fmt_tbl", NL_CAT_LOCALE);
     if (cat_fd != ((nl_catd) -1))
       {
 	/*
 	 * Get the list of characters that can't begin a line.
 	 */
-	ptr = catgets (cat_fd, 1, 1, "");
+	ptr = CATGETS(cat_fd, 1, 1, "");
 	len = strlen (ptr) + 1;
 	*cant_begin_chars = (wchar_t *) malloc (len * sizeof (wchar_t));
 	if (NULL != *cant_begin_chars &&
@@ -808,7 +808,7 @@ _DtHelpLoadMultiInfo (
 	/*
 	 * Get the list of characters that can't end a line.
 	 */
-	ptr = catgets (cat_fd, 1, 2, "");
+	ptr = CATGETS(cat_fd, 1, 2, "");
 	len = strlen (ptr) + 1;
 	*cant_end_chars = (wchar_t *) malloc (len * sizeof (wchar_t));
 	if (*cant_end_chars != NULL &&
@@ -825,10 +825,10 @@ _DtHelpLoadMultiInfo (
 	 *      0 means only between a multibyte string and
 	 *        a singlebyte string.
 	 */
-	ptr = catgets (cat_fd, 1, 3, "1");
+	ptr = CATGETS(cat_fd, 1, 3, "1");
 	*nl_to_space = atoi(ptr);
 
-	catclose (cat_fd);
+	CATCLOSE(cat_fd);
       }
     else
 #endif

cde/lib/DtHelp/Helpos.c

@@ -58,9 +58,6 @@
 #define XOS_USE_XT_LOCKING
 #include <X11/Xos_r.h>
 #include <unistd.h>
-#ifndef _SUN_OS /* don't need the nl_types.h file */
-# include <nl_types.h>
-#endif /* ! _SUN_OS */
 
 #include <X11/Intrinsic.h>
 #include <X11/Shell.h>
@@ -69,6 +66,7 @@
 /* Dt Includes */
 #include <Dt/Help.h>
 #include <Dt/DtNlUtils.h>
+#include <Dt/MsgCatP.h>
 
 #include "HelpP.h"
 #include "HelpI.h"
@@ -312,8 +310,6 @@ char *_DtHelpGetMessage(
 {
    char *msg;
    char *loc;
-   nl_catd catopen();
-   char *catgets();
    static int first = 1;
    static nl_catd nlmsg_fd;
 
@@ -337,12 +333,12 @@ char *_DtHelpGetMessage(
 	 */
 	nlmsg_fd = (nl_catd) -1;
      else
-	nlmsg_fd = catopen(CatFileName, NL_CAT_LOCALE);
+	nlmsg_fd = CATOPEN(CatFileName, NL_CAT_LOCALE);
 
      first = 0;
    }
    
-   msg=catgets(nlmsg_fd,set,n,s);
+   msg=CATGETS(nlmsg_fd,set,n,s);
    _DtHelpProcessUnlock();
    return (msg);
 }

cde/lib/DtHelp/Layout.c

@@ -65,10 +65,6 @@
 #include "SelectionI.h"
 #include "VirtFuncsI.h"
 
-#ifdef NLS16
-#include <nl_types.h>
-#endif
-
 /******************************************************************************
  *
  * Private Macros

cde/lib/DtHelp/LayoutUtil.c

@@ -64,14 +64,6 @@
 #include "StringFuncsI.h"
 #include "VirtFuncsI.h"
 
-#if defined(NLS16) || !defined(NO_MESSAGE_CATALOG)
-#include <nl_types.h>
-#endif
-
-#ifndef NL_CAT_LOCALE
-static const int NL_CAT_LOCALE = 0;
-#endif
-
 /******************************************************************************
  *
  * Private Defines

cde/lib/DtHelp/SetList.c

@@ -72,10 +72,6 @@
 #include "XInterfaceI.h"
 #include "XUICreateI.h"
 
-#ifdef NLS16
-#include <nl_types.h>
-#endif
-
 /********    Private Function Declarations    ********/
 /********    End Public Function Declarations    ********/