Use ASCII tests for character types.

* admin/merge-gnulib (GNULIB_MODULES): Add c-ctype.
* lwlib/lwlib-Xaw.c, lwlib/lwlib.c, lwlib/xlwmenu.c:
Don't include <ctype.h>; no longer needed.
* lwlib/lwlib-Xaw.c (openFont):
* lwlib/xlwmenu.c (openXftFont): Test just for ASCII digits.
* src/category.c, src/dispnew.c, src/doprnt.c, src/editfns.c, src/syntax.c
* src/term.c, src/xfns.c, src/xterm.c:
Don't include <ctype.h>; was not needed.
* src/charset.c, src/doc.c, src/fileio.c, src/font.c, src/frame.c:
* src/gtkutil.c, src/image.c, src/sysdep.c, src/xfaces.c:
Include <c-ctype.h> instead of <ctype.h>.
* src/nsterm.m: Include <c-ctype.h>.
* src/charset.c (read_hex):
* src/doc.c (Fsnarf_documentation):
* src/fileio.c (IS_DRIVE) [WINDOWSNT]:
(DRIVE_LETTER) [DOS_NT]:
(Ffile_name_directory, Fexpand_file_name)
(Fsubstitute_in_file_name):
* src/font.c (font_parse_xlfd, font_parse_fcname):
* src/frame.c (x_set_font_backend):
* src/gtkutil.c (xg_get_font):
* src/image.c (xbm_scan, xpm_scan, pbm_scan_number):
* src/nsimage.m (hexchar):
* src/nsterm.m (ns_xlfd_to_fontname):
* src/sysdep.c (system_process_attributes):
* src/xfaces.c (hash_string_case_insensitive):
Use C-locale tests instead of locale-specific tests for character
types, since we want the ASCII interpretation here, not the
interpretation suitable for whatever happens to be the current locale.

20 files changed, 86 insertions, 56 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 95140401eb..874088bb78 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,31 @@
+2012-08-16  Paul Eggert  <[email protected]>
+
+	Use ASCII tests for character types.
+	* category.c, dispnew.c, doprnt.c, editfns.c, syntax.c, term.c:
+	* xfns.c, xterm.c:
+	Don't include <ctype.h>; was not needed.
+	* charset.c, doc.c, fileio.c, font.c, frame.c, gtkutil.c, image.c:
+	* sysdep.c, xfaces.c:
+	Include <c-ctype.h> instead of <ctype.h>.
+	* nsterm.m: Include <c-ctype.h>.
+	* charset.c (read_hex):
+	* doc.c (Fsnarf_documentation):
+	* fileio.c (IS_DRIVE) [WINDOWSNT]:
+	(DRIVE_LETTER) [DOS_NT]:
+	(Ffile_name_directory, Fexpand_file_name)
+	(Fsubstitute_in_file_name):
+	* font.c (font_parse_xlfd, font_parse_fcname):
+	* frame.c (x_set_font_backend):
+	* gtkutil.c (xg_get_font):
+	* image.c (xbm_scan, xpm_scan, pbm_scan_number):
+	* nsimage.m (hexchar):
+	* nsterm.m (ns_xlfd_to_fontname):
+	* sysdep.c (system_process_attributes):
+	* xfaces.c (hash_string_case_insensitive):
+	Use C-locale tests instead of locale-specific tests for character
+	types, since we want the ASCII interpretation here, not the
+	interpretation suitable for whatever happens to be the current locale.
+
 2012-08-16  Martin Rudalics  <[email protected]>
 
 	Consistently check windows for validity/liveness
diff --git a/src/category.c b/src/category.c
index 3d5b3cff04..246a7d35a6 100644
--- a/src/category.c
+++ b/src/category.c
@@ -32,7 +32,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #define CATEGORY_INLINE EXTERN_INLINE
 
-#include <ctype.h>
 #include <setjmp.h>
 #include "lisp.h"
 #include "character.h"
diff --git a/src/charset.c b/src/charset.c
index fbbcefc491..87c16e1200 100644
--- a/src/charset.c
+++ b/src/charset.c
@@ -30,10 +30,10 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #include <stdio.h>
 #include <unistd.h>
-#include <ctype.h>
 #include <limits.h>
 #include <sys/types.h>
 #include <setjmp.h>
+#include <c-ctype.h>
 #include "lisp.h"
 #include "character.h"
 #include "charset.h"
@@ -446,7 +446,7 @@ read_hex (FILE *fp, int *eof, int *overflow)
       return 0;
     }
   n = 0;
-  while (isxdigit (c = getc (fp)))
+  while (c_isxdigit (c = getc (fp)))
     {
       if (UINT_MAX >> 4 < n)
 	*overflow = 1;
diff --git a/src/dispnew.c b/src/dispnew.c
index b82761f8ca..3288faba61 100644
--- a/src/dispnew.c
+++ b/src/dispnew.c
@@ -23,7 +23,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #include <signal.h>
 #include <stdio.h>
-#include <ctype.h>
 #include <setjmp.h>
 #include <unistd.h>
 
diff --git a/src/doc.c b/src/doc.c
index d17e90f11c..ed311d918d 100644
--- a/src/doc.c
+++ b/src/doc.c
@@ -22,11 +22,12 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #include <sys/types.h>
 #include <sys/file.h>	/* Must be after sys/types.h for USG*/
-#include <ctype.h>
 #include <setjmp.h>
 #include <fcntl.h>
 #include <unistd.h>
 
+#include <c-ctype.h>
+
 #include "lisp.h"
 #include "character.h"
 #include "buffer.h"
@@ -597,9 +598,9 @@ the same file name is found in the `doc-directory'.  */)
       {
         ptrdiff_t len;
 
-        while (*beg && isspace (*beg)) ++beg;
+        while (*beg && c_isspace (*beg)) ++beg;
 
-        for (end = beg; *end && ! isspace (*end); ++end)
+        for (end = beg; *end && ! c_isspace (*end); ++end)
           if (*end == '/') beg = end+1;  /* skip directory part  */
 
         len = end - beg;
diff --git a/src/doprnt.c b/src/doprnt.c
index 63f05cb74e..b36e946005 100644
--- a/src/doprnt.c
+++ b/src/doprnt.c
@@ -102,7 +102,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #include <config.h>
 #include <stdio.h>
-#include <ctype.h>
 #include <setjmp.h>
 #include <float.h>
 #include <unistd.h>
diff --git a/src/editfns.c b/src/editfns.c
index 5ac012c837..b7feb73378 100644
--- a/src/editfns.c
+++ b/src/editfns.c
@@ -44,7 +44,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <sys/resource.h>
 #endif
 
-#include <ctype.h>
 #include <float.h>
 #include <limits.h>
 #include <intprops.h>
diff --git a/src/fileio.c b/src/fileio.c
index eba157ea04..5991a238ff 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -30,7 +30,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <pwd.h>
 #endif
 
-#include <ctype.h>
 #include <errno.h>
 
 #ifdef HAVE_LIBSELINUX
@@ -38,6 +37,8 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <selinux/context.h>
 #endif
 
+#include <c-ctype.h>
+
 #include "lisp.h"
 #include "intervals.h"
 #include "character.h"
@@ -67,12 +68,12 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #define IS_DRIVE(x) ((x) >= 'A' && (x) <= 'z')
 #endif
 #ifdef WINDOWSNT
-#define IS_DRIVE(x) isalpha ((unsigned char) (x))
+#define IS_DRIVE(x) c_isalpha (x)
 #endif
 /* Need to lower-case the drive letter, or else expanded
    filenames will sometimes compare unequal, because
    `expand-file-name' doesn't always down-case the drive letter.  */
-#define DRIVE_LETTER(x) (tolower ((unsigned char) (x)))
+#define DRIVE_LETTER(x) c_tolower (x)
 #endif
 
 #include "systime.h"
@@ -364,7 +365,7 @@ Given a Unix syntax file name, returns a string ending in slash.  */)
 	  r += 2;
 	}
 
-      if (getdefdir (toupper ((unsigned char) *beg) - 'A' + 1, r))
+      if (getdefdir (c_toupper (*beg) - 'A' + 1, r))
 	{
 	  if (!IS_DIRECTORY_SEP (res[strlen (res) - 1]))
 	    strcat (res, "/");
@@ -1053,7 +1054,7 @@ filesystem tree, not (expand-file-name ".."  dirname).  */)
       if (!IS_DIRECTORY_SEP (nm[0]))
 	{
 	  adir = alloca (MAXPATHLEN + 1);
-	  if (!getdefdir (toupper (drive) - 'A' + 1, adir))
+	  if (!getdefdir (c_toupper (drive) - 'A' + 1, adir))
 	    adir = NULL;
 	}
       if (!adir)
@@ -1129,7 +1130,7 @@ filesystem tree, not (expand-file-name ".."  dirname).  */)
 	  adir = alloca (MAXPATHLEN + 1);
 	  if (drive)
 	    {
-	      if (!getdefdir (toupper (drive) - 'A' + 1, adir))
+	      if (!getdefdir (c_toupper (drive) - 'A' + 1, adir))
 		newdir = "/";
 	    }
 	  else
@@ -1635,7 +1636,7 @@ those `/' is discarded.  */)
 	else
 	  {
 	    o = p;
-	    while (p != endp && (isalnum (*p) || *p == '_')) p++;
+	    while (p != endp && (c_isalnum (*p) || *p == '_')) p++;
 	    s = p;
 	  }
 
@@ -1698,7 +1699,7 @@ those `/' is discarded.  */)
 	else
 	  {
 	    o = p;
-	    while (p != endp && (isalnum (*p) || *p == '_')) p++;
+	    while (p != endp && (c_isalnum (*p) || *p == '_')) p++;
 	    s = p;
 	  }
 
diff --git a/src/font.c b/src/font.c
index c3040b8aa3..5b9e4f1cfc 100644
--- a/src/font.c
+++ b/src/font.c
@@ -23,9 +23,10 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
 #include <float.h>
 #include <stdio.h>
-#include <ctype.h>
 #include <setjmp.h>
 
+#include <c-ctype.h>
+
 #include "lisp.h"
 #include "character.h"
 #include "buffer.h"
@@ -1079,7 +1080,7 @@ font_parse_xlfd (char *name, ptrdiff_t len, Lisp_Object font)
 	      p = f[XLFD_POINT_INDEX];
 	      if (*p == '[')
 		point_size = parse_matrix (p);
-	      else if (isdigit (*p))
+	      else if (c_isdigit (*p))
 		point_size = atoi (p), point_size /= 10;
 	      if (point_size >= 0)
 		ASET (font, FONT_SIZE_INDEX, make_float (point_size));
@@ -1346,7 +1347,7 @@ font_parse_fcname (char *name, ptrdiff_t len, Lisp_Object font)
 	{
 	  int decimal = 0, size_found = 1;
 	  for (q = p + 1; *q && *q != ':'; q++)
-	    if (! isdigit (*q))
+	    if (! c_isdigit (*q))
 	      {
 		if (*q != '.' || decimal)
 		  {
@@ -1474,7 +1475,7 @@ font_parse_fcname (char *name, ptrdiff_t len, Lisp_Object font)
 
       /* Scan backwards from the end, looking for a size.  */
       for (p = name + len - 1; p >= name; p--)
-	if (!isdigit (*p))
+	if (!c_isdigit (*p))
 	  break;
 
       if ((p < name + len - 1) && ((p + 1 == name) || *p == ' '))
diff --git a/src/frame.c b/src/frame.c
index ea682835a8..9dabae55ab 100644
--- a/src/frame.c
+++ b/src/frame.c
@@ -20,10 +20,12 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
 
 #include <stdio.h>
-#include <ctype.h>
 #include <errno.h>
 #include <limits.h>
 #include <setjmp.h>
+
+#include <c-ctype.h>
+
 #include "lisp.h"
 #include "character.h"
 #ifdef HAVE_X_WINDOWS
@@ -3271,7 +3273,7 @@ x_set_font_backend (struct frame *f, Lisp_Object new_value, Lisp_Object old_valu
       new_value = Qnil;
       while (*p0)
 	{
-	  while (*p1 && ! isspace (*p1) && *p1 != ',') p1++;
+	  while (*p1 && ! c_isspace (*p1) && *p1 != ',') p1++;
 	  if (p0 < p1)
 	    new_value = Fcons (Fintern (make_string (p0, p1 - p0), Qnil),
 			       new_value);
@@ -3279,7 +3281,7 @@ x_set_font_backend (struct frame *f, Lisp_Object new_value, Lisp_Object old_valu
 	    {
 	      int c;
 
-	      while ((c = *++p1) && isspace (c));
+	      while ((c = *++p1) && c_isspace (c));
 	    }
 	  p0 = p1;
 	}
diff --git a/src/gtkutil.c b/src/gtkutil.c
index a4de47f073..2941605d44 100644
--- a/src/gtkutil.c
+++ b/src/gtkutil.c
@@ -24,7 +24,9 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <signal.h>
 #include <stdio.h>
 #include <setjmp.h>
-#include <ctype.h>
+
+#include <c-ctype.h>
+
 #include "lisp.h"
 #include "xterm.h"
 #include "blockinput.h"
@@ -2072,7 +2074,7 @@ xg_get_font (FRAME_PTR f, const char *default_name)
       if (p)
         {
           char *ep = p+1;
-          while (isdigit (*ep))
+          while (c_isdigit (*ep))
             ++ep;
           if (*ep == '\0') *p = ' ';
         }
diff --git a/src/image.c b/src/image.c
index 8a318c2f6e..f2778165ec 100644
--- a/src/image.c
+++ b/src/image.c
@@ -20,7 +20,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <config.h>
 #include <stdio.h>
 #include <math.h>
-#include <ctype.h>
 #include <unistd.h>
 
 #ifdef HAVE_PNG
@@ -33,6 +32,8 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #include <setjmp.h>
 
+#include <c-ctype.h>
+
 /* This makes the fields of a Display accessible, in Xlib header files.  */
 
 #define XLIB_ILLEGAL_ACCESS
@@ -2405,12 +2406,12 @@ xbm_scan (unsigned char **s, unsigned char *end, char *sval, int *ival)
  loop:
 
   /* Skip white space.  */
-  while (*s < end && (c = *(*s)++, isspace (c)))
+  while (*s < end && (c = *(*s)++, c_isspace (c)))
     ;
 
   if (*s >= end)
     c = 0;
-  else if (isdigit (c))
+  else if (c_isdigit (c))
     {
       int value = 0, digit;
 
@@ -2422,7 +2423,7 @@ xbm_scan (unsigned char **s, unsigned char *end, char *sval, int *ival)
 	      while (*s < end)
 		{
 		  c = *(*s)++;
-		  if (isdigit (c))
+		  if (c_isdigit (c))
 		    digit = c - '0';
 		  else if (c >= 'a' && c <= 'f')
 		    digit = c - 'a' + 10;
@@ -2433,11 +2434,11 @@ xbm_scan (unsigned char **s, unsigned char *end, char *sval, int *ival)
 		  value = 16 * value + digit;
 		}
 	    }
-	  else if (isdigit (c))
+	  else if (c_isdigit (c))
 	    {
 	      value = c - '0';
 	      while (*s < end
-		     && (c = *(*s)++, isdigit (c)))
+		     && (c = *(*s)++, c_isdigit (c)))
 		value = 8 * value + c - '0';
 	    }
 	}
@@ -2445,7 +2446,7 @@ xbm_scan (unsigned char **s, unsigned char *end, char *sval, int *ival)
 	{
 	  value = c - '0';
 	  while (*s < end
-		 && (c = *(*s)++, isdigit (c)))
+		 && (c = *(*s)++, c_isdigit (c)))
 	    value = 10 * value + c - '0';
 	}
 
@@ -2454,11 +2455,11 @@ xbm_scan (unsigned char **s, unsigned char *end, char *sval, int *ival)
       *ival = value;
       c = XBM_TK_NUMBER;
     }
-  else if (isalpha (c) || c == '_')
+  else if (c_isalpha (c) || c == '_')
     {
       *sval++ = c;
       while (*s < end
-	     && (c = *(*s)++, (isalnum (c) || c == '_')))
+	     && (c = *(*s)++, (c_isalnum (c) || c == '_')))
 	*sval++ = c;
       *sval = 0;
       if (*s < end)
@@ -3661,16 +3662,17 @@ xpm_scan (const unsigned char **s,
   while (*s < end)
     {
       /* Skip white-space.  */
-      while (*s < end && (c = *(*s)++, isspace (c)))
+      while (*s < end && (c = *(*s)++, c_isspace (c)))
 	;
 
       /* gnus-pointer.xpm uses '-' in its identifier.
 	 sb-dir-plus.xpm uses '+' in its identifier.  */
-      if (isalpha (c) || c == '_' || c == '-' || c == '+')
+      if (c_isalpha (c) || c == '_' || c == '-' || c == '+')
 	{
 	  *beg = *s - 1;
 	  while (*s < end
-		 && (c = **s, isalnum (c) || c == '_' || c == '-' || c == '+'))
+		 && (c = **s, c_isalnum (c)
+		     || c == '_' || c == '-' || c == '+'))
 	      ++*s;
 	  *len = *s - *beg;
 	  return XPM_TK_IDENT;
@@ -5014,7 +5016,7 @@ pbm_scan_number (unsigned char **s, unsigned char *end)
   while (*s < end)
     {
       /* Skip white-space.  */
-      while (*s < end && (c = *(*s)++, isspace (c)))
+      while (*s < end && (c = *(*s)++, c_isspace (c)))
 	;
 
       if (c == '#')
@@ -5023,11 +5025,11 @@ pbm_scan_number (unsigned char **s, unsigned char *end)
 	  while (*s < end && (c = *(*s)++, c != '\n'))
 	    ;
 	}
-      else if (isdigit (c))
+      else if (c_isdigit (c))
 	{
 	  /* Read decimal number.  */
 	  val = c - '0';
-	  while (*s < end && (c = *(*s)++, isdigit (c)))
+	  while (*s < end && (c = *(*s)++, c_isdigit (c)))
 	    val = 10 * val + c - '0';
 	  break;
 	}
@@ -8554,7 +8556,7 @@ gs_load (struct frame *f, struct image *img)
      don't either.  Let the Lisp loader use `unwind-protect' instead.  */
   printnum1 = FRAME_X_WINDOW (f);
   printnum2 = img->pixmap;
-  window_and_pixmap_id 
+  window_and_pixmap_id
     = make_formatted_string (buffer, "%"pMu" %"pMu, printnum1, printnum2);
 
   printnum1 = FRAME_FOREGROUND_PIXEL (f);
diff --git a/src/nsimage.m b/src/nsimage.m
index 1479294948..8a8a3ddaae 100644
--- a/src/nsimage.m
+++ b/src/nsimage.m
@@ -302,7 +302,7 @@ static EmacsImage *ImageList = nil;
                   [bmRep release];
                   return nil;
                 }
-#define hexchar(x) (isdigit (x) ? x - '0' : x - 'a' + 10)
+#define hexchar(x) ('0' <= (x) && (x) <= '9' ? (x) - '0' : (x) - 'a' + 10)
               s1 = *s++;
               s2 = *s++;
               c = hexchar (s1) * 0x10 + hexchar (s2);
@@ -501,4 +501,3 @@ static EmacsImage *ImageList = nil;
 }
 
 @end
-
diff --git a/src/nsterm.m b/src/nsterm.m
index 76e6ee8fb4..a628a248c7 100644
--- a/src/nsterm.m
+++ b/src/nsterm.m
@@ -36,6 +36,8 @@ GNUstep port and post-20 update by Adrian Robert ([email protected])
 #include <signal.h>
 #include <unistd.h>
 #include <setjmp.h>
+
+#include <c-ctype.h>
 #include <c-strcase.h>
 #include <ftoastr.h>
 
@@ -6785,20 +6787,20 @@ ns_xlfd_to_fontname (const char *xlfd)
 
   /* undo hack in ns_fontname_to_xlfd, converting '$' to '-', '_' to ' '
      also uppercase after '-' or ' ' */
-  name[0] = toupper (name[0]);
+  name[0] = c_toupper (name[0]);
   for (len =strlen (name), i =0; i<len; i++)
     {
       if (name[i] == '$')
         {
           name[i] = '-';
           if (i+1<len)
-            name[i+1] = toupper (name[i+1]);
+            name[i+1] = c_toupper (name[i+1]);
         }
       else if (name[i] == '_')
         {
           name[i] = ' ';
           if (i+1<len)
-            name[i+1] = toupper (name[i+1]);
+            name[i+1] = c_toupper (name[i+1]);
         }
     }
 /*fprintf (stderr, "converted '%s' to '%s'\n",xlfd,name);  */
diff --git a/src/syntax.c b/src/syntax.c
index 1cbad1ae0a..69965d1d82 100644
--- a/src/syntax.c
+++ b/src/syntax.c
@@ -20,7 +20,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #include <config.h>
 
-#include <ctype.h>
 #include <sys/types.h>
 #include <setjmp.h>
 #include "lisp.h"
diff --git a/src/sysdep.c b/src/sysdep.c
index 01ca905a98..1dbe8938e4 100644
--- a/src/sysdep.c
+++ b/src/sysdep.c
@@ -21,7 +21,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #define SYSTIME_INLINE EXTERN_INLINE
 
-#include <ctype.h>
 #include <signal.h>
 #include <stdio.h>
 #include <setjmp.h>
@@ -33,6 +32,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <unistd.h>
 
 #include <allocator.h>
+#include <c-ctype.h>
 #include <careadlinkat.h>
 #include <ignore-value.h>
 #include <utimens.h>
@@ -2733,7 +2733,7 @@ system_process_attributes (Lisp_Object pid)
 	  if (emacs_read (fd, &ch, 1) != 1)
 	    break;
 	  c = ch;
-	  if (isspace (c) || c == '\\')
+	  if (c_isspace (c) || c == '\\')
 	    cmdline_size++;	/* for later quoting, see below */
 	}
       if (cmdline_size)
@@ -2757,7 +2757,7 @@ system_process_attributes (Lisp_Object pid)
 	  for (p = cmdline; p < cmdline + nread; p++)
 	    {
 	      /* Escape-quote whitespace and backslashes.  */
-	      if (isspace (*p) || *p == '\\')
+	      if (c_isspace (*p) || *p == '\\')
 		{
 		  memmove (p + 1, p, nread - (p - cmdline));
 		  nread++;
diff --git a/src/term.c b/src/term.c
index 514c7ad11e..c5cec3062e 100644
--- a/src/term.c
+++ b/src/term.c
@@ -21,7 +21,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #include <config.h>
 #include <stdio.h>
-#include <ctype.h>
 #include <errno.h>
 #include <sys/file.h>
 #include <sys/time.h>
diff --git a/src/xfaces.c b/src/xfaces.c
index ed372c6b41..7491802466 100644
--- a/src/xfaces.c
+++ b/src/xfaces.c
@@ -279,7 +279,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #endif /* HAVE_X_WINDOWS */
 
-#include <ctype.h>
+#include <c-ctype.h>
 
 /* Number of pt per inch (from the TeXbook).  */
 
@@ -4059,7 +4059,7 @@ hash_string_case_insensitive (Lisp_Object string)
   unsigned hash = 0;
   eassert (STRINGP (string));
   for (s = SDATA (string); *s; ++s)
-    hash = (hash << 1) ^ tolower (*s);
+    hash = (hash << 1) ^ c_tolower (*s);
   return hash;
 }
 
diff --git a/src/xfns.c b/src/xfns.c
index 2e7334b7d7..a9d22e7d3c 100644
--- a/src/xfns.c
+++ b/src/xfns.c
@@ -49,7 +49,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #ifdef HAVE_X_WINDOWS
 
-#include <ctype.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 
diff --git a/src/xterm.c b/src/xterm.c
index 1b746f87d5..b1a73d0799 100644
--- a/src/xterm.c
+++ b/src/xterm.c
@@ -50,7 +50,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include "systime.h"
 
 #include <fcntl.h>
-#include <ctype.h>
 #include <errno.h>
 #include <setjmp.h>
 #include <sys/stat.h>