Fix the MS-Windows build as followup to Gnulib regex import

* lib-src/ntlib.c (nl_langinfo): New function.  (Bug#32194)

1 files changed, 67 insertions, 0 deletions

diff --git a/lib-src/ntlib.c b/lib-src/ntlib.c
index 95512854839..4ca521d2775 100644
--- a/lib-src/ntlib.c
+++ b/lib-src/ntlib.c
@@ -31,6 +31,10 @@ along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
 #include <ctype.h>
 #include <sys/timeb.h>
 #include <mbstring.h>
+#include <locale.h>
+
+#include <nl_types.h>
+#include <langinfo.h>
 
 #include "ntlib.h"
 
@@ -423,3 +427,66 @@ sys_open (const char * path, int oflag, int mode)
 {
   return _open (path, oflag, mode);
 }
+
+/* Emulation of nl_langinfo that supports only CODESET.
+   Used in Gnulib regex.c.  */
+char *
+nl_langinfo (nl_item item)
+{
+  switch (item)
+    {
+      case CODESET:
+        {
+          /* Shamelessly stolen from Gnulib's nl_langinfo.c, modulo
+             CPP directives.  */
+          static char buf[2 + 10 + 1];
+          char const *locale = setlocale (LC_CTYPE, NULL);
+          char *codeset = buf;
+          size_t codesetlen;
+          codeset[0] = '\0';
+
+          if (locale && locale[0])
+            {
+              /* If the locale name contains an encoding after the
+                 dot, return it.  */
+              char *dot = strchr (locale, '.');
+
+              if (dot)
+                {
+                  /* Look for the possible @... trailer and remove it,
+                     if any.  */
+                  char *codeset_start = dot + 1;
+                  char const *modifier = strchr (codeset_start, '@');
+
+                  if (! modifier)
+                    codeset = codeset_start;
+                  else
+                    {
+                      codesetlen = modifier - codeset_start;
+                      if (codesetlen < sizeof buf)
+                        {
+                          codeset = memcpy (buf, codeset_start, codesetlen);
+                          codeset[codesetlen] = '\0';
+                        }
+                    }
+                }
+            }
+          /* If setlocale is successful, it returns the number of the
+             codepage, as a string.  Otherwise, fall back on Windows
+             API GetACP, which returns the locale's codepage as a
+             number (although this doesn't change according to what
+             the 'setlocale' call specified).  Either way, prepend
+             "CP" to make it a valid codeset name.  */
+          codesetlen = strlen (codeset);
+          if (0 < codesetlen && codesetlen < sizeof buf - 2)
+            memmove (buf + 2, codeset, codesetlen + 1);
+          else
+            sprintf (buf + 2, "%u", GetACP ());
+          codeset = memcpy (buf, "CP", 2);
+
+          return codeset;
+        }
+      default:
+        return (char *) "";
+    }
+}