Fix length returned from sys_cp_wcstombs in case nwc > # of wchars

	* strfuncs.cc (sys_cp_wcstombs): Always return number of multibytes
	without trailing NUL as the documentation implies.  Throughout Cygwin,
	fix usage to align to this pattern.
	* fhandler_process.cc (format_process_winexename): Drop trailing NUL
	and LF from output.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>

9 files changed, 23 insertions, 14 deletions

diff --git a/winsup/cygwin/ChangeLog b/winsup/cygwin/ChangeLog
index 4cbbd0b10..7cd19b52a 100644
--- a/winsup/cygwin/ChangeLog
+++ b/winsup/cygwin/ChangeLog
@@ -1,3 +1,11 @@
+2015-10-22  Corinna Vinschen  <corinna@vinschen.de>
+
+	* strfuncs.cc (sys_cp_wcstombs): Always return number of multibytes
+	without trailing NUL as the documentation implies.  Throughout Cygwin,
+	fix usage to align to this pattern.
+	* fhandler_process.cc (format_process_winexename): Drop trailing NUL
+	and LF from output.
+
 2015-10-21  Corinna Vinschen  <corinna@vinschen.de>
 
 	* thread.cc (pthread_getattr_np): Fix memory leak, remove usage of
diff --git a/winsup/cygwin/dcrt0.cc b/winsup/cygwin/dcrt0.cc
index 8ac7f4cd5..3d293f609 100644
--- a/winsup/cygwin/dcrt0.cc
+++ b/winsup/cygwin/dcrt0.cc
@@ -952,7 +952,7 @@ dll_crt0_1 (void *)
   if (!__argc)
     {
       PWCHAR wline = GetCommandLineW ();
-      size_t size = sys_wcstombs (NULL, 0, wline);
+      size_t size = sys_wcstombs (NULL, 0, wline) + 1;
       char *line = (char *) alloca (size);
       sys_wcstombs (line, size, wline);
 
diff --git a/winsup/cygwin/environ.cc b/winsup/cygwin/environ.cc
index 8f25fb19e..ab6511be1 100644
--- a/winsup/cygwin/environ.cc
+++ b/winsup/cygwin/environ.cc
@@ -895,7 +895,7 @@ getwinenveq (const char *name, size_t namelen, int x)
   int totlen = GetEnvironmentVariableW (name0, valbuf, 32768);
   if (totlen > 0)
     {
-      totlen = sys_wcstombs (NULL, 0, valbuf);
+      totlen = sys_wcstombs (NULL, 0, valbuf) + 1;
       if (x == HEAP_1_STR)
 	totlen += namelen;
       else
diff --git a/winsup/cygwin/fhandler_process.cc b/winsup/cygwin/fhandler_process.cc
index d3ee874cd..516fbe32c 100644
--- a/winsup/cygwin/fhandler_process.cc
+++ b/winsup/cygwin/fhandler_process.cc
@@ -568,9 +568,9 @@ format_process_winexename (void *data, char *&destbuf)
   _pinfo *p = (_pinfo *) data;
   size_t len = sys_wcstombs (NULL, 0, p->progname);
   destbuf = (char *) crealloc_abort (destbuf, len + 1);
-  sys_wcstombs (destbuf, len, p->progname);
-  destbuf[len] = '\n';
-  return len + 1;
+  /* With trailing \0 for backward compat reasons. */
+  sys_wcstombs (destbuf, len + 1, p->progname);
+  return len;
 }
 
 struct heap_info
diff --git a/winsup/cygwin/fhandler_registry.cc b/winsup/cygwin/fhandler_registry.cc
index fbdb44065..666363725 100644
--- a/winsup/cygwin/fhandler_registry.cc
+++ b/winsup/cygwin/fhandler_registry.cc
@@ -286,7 +286,7 @@ multi_wcstombs (char *dst, size_t len, const wchar_t *src, size_t nwc)
 
   while (nwc)
     {
-      siz = sys_wcstombs (dst, len, src, nwc);
+      siz = sys_wcstombs (dst, len, src, nwc) + 1;
       sum += siz;
       if (dst)
 	{
@@ -555,7 +555,8 @@ fhandler_registry::fstat (struct stat *buf)
 		      else
 			buf->st_size = sys_wcstombs (NULL, 0,
 						     (wchar_t *) tmpbuf,
-						     dwSize / sizeof (wchar_t));
+						     dwSize / sizeof (wchar_t))
+				       + 1;
 		      if (tmpbuf)
 			free (tmpbuf);
 		    }
@@ -972,7 +973,7 @@ fhandler_registry::fill_filebuf ()
 	}
       if (type == REG_SZ || type == REG_EXPAND_SZ || type == REG_LINK)
 	bufalloc = sys_wcstombs (NULL, 0, (wchar_t *) tmpbuf,
-				 size / sizeof (wchar_t));
+				 size / sizeof (wchar_t)) + 1;
       else if (type == REG_MULTI_SZ)
 	bufalloc = multi_wcstombs (NULL, 0, (wchar_t *) tmpbuf,
 				   size / sizeof (wchar_t));
diff --git a/winsup/cygwin/net.cc b/winsup/cygwin/net.cc
index 20b4d3cb1..0f3946a4d 100644
--- a/winsup/cygwin/net.cc
+++ b/winsup/cygwin/net.cc
@@ -2107,7 +2107,7 @@ get_friendlyname (struct ifall *ifp, PIP_ADAPTER_ADDRESSES pap)
 				 &ifp->ifa_frndlyname;
   iff->ifrf_len = sys_wcstombs (iff->ifrf_friendlyname,
 				IFRF_FRIENDLYNAMESIZ,
-				pap->FriendlyName);
+				pap->FriendlyName) + 1;
 }
 
 static void
diff --git a/winsup/cygwin/path.cc b/winsup/cygwin/path.cc
index 488d4e6e0..54c96fee5 100644
--- a/winsup/cygwin/path.cc
+++ b/winsup/cygwin/path.cc
@@ -2167,7 +2167,7 @@ symlink_info::check_shortcut (HANDLE h)
 	{
 	  char *tmpbuf = tp.c_get ();
 	  if (sys_wcstombs (tmpbuf, NT_MAX_PATH, (PWCHAR) (cp + 2))
-	      > SYMLINK_MAX + 1)
+	      > SYMLINK_MAX)
 	    return 0;
 	  res = posixify (tmpbuf);
 	}
@@ -2248,7 +2248,7 @@ symlink_info::check_sysfile (HANDLE h)
 	    srcbuf += 2;
 	  char *tmpbuf = tp.c_get ();
 	  if (sys_wcstombs (tmpbuf, NT_MAX_PATH, (PWCHAR) srcbuf)
-	      > SYMLINK_MAX + 1)
+	      > SYMLINK_MAX)
 	    debug_printf ("symlink string too long");
 	  else
 	    res = posixify (tmpbuf);
@@ -2368,7 +2368,7 @@ symlink_info::check_nfs_symlink (HANDLE h)
       PWCHAR spath = (PWCHAR)
 		     (pffei->EaName + pffei->EaNameLength + 1);
       res = sys_wcstombs (contents, SYMLINK_MAX + 1,
-			  spath, pffei->EaValueLength) - 1;
+			  spath, pffei->EaValueLength);
       pflags |= PATH_SYMLINK;
     }
   return res;
diff --git a/winsup/cygwin/strfuncs.cc b/winsup/cygwin/strfuncs.cc
index 94ce82ce5..0be0f53f2 100644
--- a/winsup/cygwin/strfuncs.cc
+++ b/winsup/cygwin/strfuncs.cc
@@ -474,7 +474,6 @@ sys_cp_wcstombs (wctomb_p f_wctomb, const char *charset, char *dst, size_t len,
 	}
       if (n + bytes <= len)
 	{
-	  n += bytes;
 	  if (dst)
 	    {
 	      for (int i = 0; i < bytes; ++i)
@@ -482,6 +481,7 @@ sys_cp_wcstombs (wctomb_p f_wctomb, const char *charset, char *dst, size_t len,
 	    }
 	  if (*pwcs++ == 0x00)
 	    break;
+	  n += bytes;
 	}
       else
 	break;
diff --git a/winsup/cygwin/uinfo.cc b/winsup/cygwin/uinfo.cc
index da5809f64..df7d42f8e 100644
--- a/winsup/cygwin/uinfo.cc
+++ b/winsup/cygwin/uinfo.cc
@@ -56,7 +56,7 @@ cygheap_user::init ()
   if (GetEnvironmentVariableW (L"USERNAME", user_name, user_name_len)
       || GetEnvironmentVariableW (L"USER", user_name, user_name_len))
     {
-      char mb_user_name[user_name_len = sys_wcstombs (NULL, 0, user_name)];
+      char mb_user_name[user_name_len = sys_wcstombs (NULL, 0, user_name) + 1];
       sys_wcstombs (mb_user_name, user_name_len, user_name);
       set_name (mb_user_name);
     }