[6908] Fix crashes in mbrtowc on MS-Windows.

[Eli Zaretskii]

Revision: 6908
          http://svn.sv.gnu.org/viewvc/?view=rev&root=texinfo&revision=6908
Author:   eliz
Date:     2016-01-01 18:58:36 +0000 (Fri, 01 Jan 2016)
Log Message:
-----------
Fix crashes in mbrtowc on MS-Windows.

Modified Paths:
--------------
    trunk/ChangeLog
    trunk/tp/Texinfo/Convert/XSParagraph/xspara.c

Modified: trunk/ChangeLog
===================================================================
--- trunk/ChangeLog     2016-01-01 18:42:32 UTC (rev 6907)
+++ trunk/ChangeLog     2016-01-01 18:58:36 UTC (rev 6908)
@@ -1,3 +1,9 @@
+2016-01-01  Eli Zaretskii  <address@hidden>
+
+       * tp/Texinfo/Convert/XSParagraph/xspara.c (mbrtowc): Don't try to
+       convert more bytes than a single UTF-8 sequence at the beginning
+       of the argument string: otherwise MultiByteToWideChar fails.
+
 2016-01-01  Karl Berry  <address@hidden>
 
        * makeinfo/README,

Modified: trunk/tp/Texinfo/Convert/XSParagraph/xspara.c
===================================================================
--- trunk/tp/Texinfo/Convert/XSParagraph/xspara.c       2016-01-01 18:42:32 UTC 
(rev 6907)
+++ trunk/tp/Texinfo/Convert/XSParagraph/xspara.c       2016-01-01 18:58:36 UTC 
(rev 6908)
@@ -126,13 +126,15 @@
 mbrtowc (wchar_t * __restrict__ pwc, const char * __restrict__ mbs, size_t n,
         mbstate_t * __restrict__ ps)
 {
+  int len = mbrlen (mbs, n, ps);
+
   if (mbs == NULL)
     return 0;
   else
     {
       wchar_t wc[2];
       size_t n_utf16 = MultiByteToWideChar (CP_UTF8, MB_ERR_INVALID_CHARS,
-                                           mbs, n, wc, 2);
+                                           mbs, len, wc, 2);
       if (n_utf16 == 0)
        {
          errno = EILSEQ;
@@ -153,7 +155,7 @@
       if (pwc != NULL)
        *pwc = wc[0];
 
-      return mbrlen (mbs, n, ps);
+      return len;
     }
 }