core: Avoid truncation of error message in the middle of a character.

* configure.ac (AM_LANGINFO_CODESET): Add.
* src/strerror.c (_gpg_strerror_r): Check the boundary of character.

--

GnuPG-bug-id: 5048
Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>

1 files changed, 25 insertions, 0 deletions

diff --git a/src/strerror.c b/src/strerror.c
index 4cce17f..fb1bebf 100644
--- a/src/strerror.c
+++ b/src/strerror.c
@@ -32,6 +32,10 @@
 #include "gettext.h"
 #include "err-codes.h"
 
+#if defined(ENABLE_NLS) && defined(HAVE_LANGINFO_CODESET)
+#include <langinfo.h>
+#endif
+
 /* Return a pointer to a string containing a description of the error
    code in the error value ERR.  This function is not thread-safe.  */
 const char *
@@ -169,9 +173,30 @@ _gpg_strerror_r (gpg_error_t err, char *buf, size_t buflen)
   errstr = dgettext (PACKAGE, msgstr + msgidx[msgidxof (code)]);
   errstr_len = strlen (errstr) + 1;
   cpy_len = errstr_len < buflen ? errstr_len : buflen;
+#if defined(ENABLE_NLS) && defined(HAVE_LANGINFO_CODESET)
+  /* Avoid truncation in the middle of "character" boundary.  */
+  if (buflen && errstr_len > buflen
+      && ((unsigned char)errstr[cpy_len-1] & 0xC0) == 0x80
+      && !strcasecmp (nl_langinfo (CODESET), "UTF-8"))
+    {
+      /* Go back to the boundary */
+      for (; cpy_len; cpy_len--)
+        if (((unsigned char)errstr[cpy_len-1] & 0xC0) != 0x80)
+          break;
+      memcpy (buf, errstr, cpy_len);
+      memset (buf+cpy_len, 0, buflen - cpy_len);
+    }
+  else
+    {
+      memcpy (buf, errstr, cpy_len);
+      if (buflen)
+        buf[buflen - 1] = '\0';
+    }
+#else
   memcpy (buf, errstr, cpy_len);
   if (buflen)
     buf[buflen - 1] = '\0';
+#endif
 
   return cpy_len == errstr_len ? 0 : ERANGE;
 }