drop the isblank/iswblank fallback functions

Switch over to gnulib for these.

autogen.sh

@@ -7,6 +7,8 @@ gnulib_hash="4084b3a1094372b960ce4a97634e08f4538c8bdd"
 modules="
 	getdelim
 	getline
+	isblank
+	iswblank
 	strcase
 	strcasestr-simple
 	strnlen

configure.ac

@@ -473,10 +473,10 @@ int main(void)
 
 dnl Checks for functions.
 
-AC_CHECK_FUNCS(isblank snprintf vsnprintf)
+AC_CHECK_FUNCS(snprintf vsnprintf)
 
 if test "x$enable_utf8" != xno; then
-    AC_CHECK_FUNCS(iswalnum iswblank iswpunct iswspace nl_langinfo mblen mbstowcs mbtowc wctomb wcwidth)
+    AC_CHECK_FUNCS(iswalnum iswpunct iswspace nl_langinfo mblen mbstowcs mbtowc wctomb wcwidth)
 fi
 
 if test x$ac_cv_func_snprintf = xno; then

src/chars.c

@@ -61,22 +61,6 @@ char *addstrings(char* str1, size_t len1, char* str2, size_t len2)
     return str1;
 }
 
-#ifndef HAVE_ISBLANK
-/* This function is equivalent to isblank(). */
-bool nisblank(int c)
-{
-    return isspace(c) && (c == '\t' || !is_cntrl_char(c));
-}
-#endif
-
-#if !defined(HAVE_ISWBLANK) && defined(ENABLE_UTF8)
-/* This function is equivalent to iswblank(). */
-bool niswblank(wchar_t wc)
-{
-    return iswspace(wc) && (wc == '\t' || !is_cntrl_wchar(wc));
-}
-#endif
-
 /* Return TRUE if the value of c is in byte range, and FALSE otherwise. */
 bool is_byte(int c)
 {

src/nano.h

@@ -128,16 +128,6 @@
 #define vsnprintf g_vsnprintf
 #endif
 
-/* If no isblank(), iswblank(), strcasecmp(), strncasecmp(),
- * strcasestr(), strnlen(), getdelim(), or getline(), use the versions
- * we have. */
-#ifndef HAVE_ISBLANK
-#define isblank nisblank
-#endif
-#ifndef HAVE_ISWBLANK
-#define iswblank niswblank
-#endif
-
 /* If we aren't using ncurses with mouse support, turn the mouse support
  * off, as it's useless then. */
 #ifndef NCURSES_MOUSE_VERSION

src/proto.h

@@ -193,12 +193,6 @@ void utf8_init(void);
 bool using_utf8(void);
 #endif
 char *addstrings(char* str1, size_t len1, char* str2, size_t len2);
-#ifndef HAVE_ISBLANK
-bool nisblank(int c);
-#endif
-#if !defined(HAVE_ISWBLANK) && defined(ENABLE_UTF8)
-bool niswblank(wchar_t wc);
-#endif
 bool is_byte(int c);
 bool is_alpha_mbchar(const char *c);
 bool is_alnum_mbchar(const char *c);