1 files changed, 123 insertions, 0 deletions
diff --git a/lib/mbsrtowcs-impl.h b/lib/mbsrtowcs-impl.h
new file mode 100644
index 0000000..0b068b2
--- /dev/null
+++ b/lib/mbsrtowcs-impl.h
@@ -0,0 +1,123 @@
+/* Convert string to wide string.
+   Copyright (C) 2008-2023 Free Software Foundation, Inc.
+   Written by Bruno Haible <bruno@clisp.org>, 2008.
+
+   This file is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as
+   published by the Free Software Foundation; either version 2.1 of the
+   License, or (at your option) any later version.
+
+   This file is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
+
+size_t
+FUNC (DCHAR_T *dest, const char **srcp, size_t len, mbstate_t *ps)
+{
+  if (ps == NULL)
+    ps = &INTERNAL_STATE;
+  {
+    const char *src = *srcp;
+
+    if (dest != NULL)
+      {
+        DCHAR_T *destptr = dest;
+
+        for (; len > 0; destptr++, len--)
+          {
+            size_t src_avail;
+            size_t ret;
+
+            /* An optimized variant of
+               src_avail = strnlen1 (src, MB_LEN_MAX);  */
+            if (src[0] == '\0')
+              src_avail = 1;
+            else if (src[1] == '\0')
+              src_avail = 2;
+            else if (src[2] == '\0')
+              src_avail = 3;
+            else if (MB_LEN_MAX <= 4 || src[3] == '\0')
+              src_avail = 4;
+            else
+              src_avail = 4 + strnlen1 (src + 4, MB_LEN_MAX - 4);
+
+            /* Parse the next multibyte character.  */
+            ret = MBRTOWC (destptr, src, src_avail, ps);
+
+            if (ret == (size_t)(-2))
+              /* Encountered a multibyte character that extends past a '\0' byte
+                 or that is longer than MB_LEN_MAX bytes.  Cannot happen.  */
+              abort ();
+
+            if (ret == (size_t)(-1))
+              goto bad_input;
+            if (ret == 0)
+              {
+                src = NULL;
+                /* Here mbsinit (ps).  */
+                break;
+              }
+            if (!(USES_C32 && ret == (size_t)(-3)))
+              src += ret;
+          }
+
+        *srcp = src;
+        return destptr - dest;
+      }
+    else
+      {
+        /* Ignore dest and len, don't store *srcp at the end, and
+           don't clobber *ps.  */
+        mbstate_t state = *ps;
+        size_t totalcount = 0;
+
+        for (;; totalcount++)
+          {
+            size_t src_avail;
+            size_t ret;
+
+            /* An optimized variant of
+               src_avail = strnlen1 (src, MB_LEN_MAX);  */
+            if (src[0] == '\0')
+              src_avail = 1;
+            else if (src[1] == '\0')
+              src_avail = 2;
+            else if (src[2] == '\0')
+              src_avail = 3;
+            else if (MB_LEN_MAX <= 4 || src[3] == '\0')
+              src_avail = 4;
+            else
+              src_avail = 4 + strnlen1 (src + 4, MB_LEN_MAX - 4);
+
+            /* Parse the next multibyte character.  */
+            ret = MBRTOWC (NULL, src, src_avail, &state);
+
+            if (ret == (size_t)(-2))
+              /* Encountered a multibyte character that extends past a '\0' byte
+                 or that is longer than MB_LEN_MAX bytes.  Cannot happen.  */
+              abort ();
+
+            if (ret == (size_t)(-1))
+              goto bad_input2;
+            if (ret == 0)
+              {
+                /* Here mbsinit (&state).  */
+                break;
+              }
+            src += ret;
+          }
+
+        return totalcount;
+      }
+
+   bad_input:
+    *srcp = src;
+   bad_input2:
+    errno = EILSEQ;
+    return (size_t)(-1);
+  }
+}