Make paths' WCS->MBS conversion explicit

	* dcrt0.cc (dll_crt0_1), dtable.cc (handle_to_fn), environ.cc
	(environ_init, getwinenveq, build_env), external.cc
	(fillout_pinfo), fhandler_disk_file.cc (__DIR_mounts::eval_ino,
	fhandler_disk_file::readdir_helper), fhandler_netdrive.cc
	(fhandler_netdrive::readdir), fhandler_process.cc
	(format_process_winexename, format_process_maps,
	format_process_stat, format_process_status), fhandler_procsys.cc
	(fill_filebuf, fhandler_procsys::readdir), mount.cc
	(fs_info::update, mount_info::create_root_entry,
	mount_info::conv_to_posix_path, mount_info::from_fstab_line),
	nlsfuncs.cc (internal_setlocale), path.cc (path_conv::check,
	sysmlink_info::check_shortcut, symlink_info::check_sysfile,
	symlink_info::check_reparse_point,
	symlink_info::check_nfs_symlink, cygwin_conv_path,
	cygwin_conv_path_list, cwdstuff::get_error_desc, cwdstuff::get),
	strfuncs.cc (sys_wcstombs_no_path, sys_wcstombs_alloc_no_path),
	uinfo.cc (ontherange, fetch_from_path, cygheap_pwdgrp::get_home,
	cygheap_pwdgrp::get_shell, cygheap_pwdgrp::get_gecos), wchar.h
	(sys_wcstombs_no_path, sys_wcstombs_alloc_no_path): Convert call
	sites of the sys_wcstombs*() family to specify explicitly when the
	parameter refers to a path or file name, to avoid future
	misconversions.

Detailed explanation:

The sys_wcstombs() function contains special handling for paths/file
names, to work around file name restriction on Windows that are
unexpected in the POSIX context of Cygwin.

We actually do not want that special handling for WCS strings that
do *not* refer to paths or file names.

Neither do we want to convert those special file names unless they come
from inside Cygwin: if the source of the string value is the Windows API,
we *know* it cannot be such a special file name because Windows itself
would not be able to handle it in the way Cygwin does.

So let's switch the previous sys_wcstombs()/sys_wcstombs_no_path() (and
the *_alloc* variant) around to sys_wcstombs_path()/sys_wcstombs(). We do
this for several reasons:

- whenever a call site wants to convert a WCS representation of a path or
  file name to an MBS one, it should be made very clear that we *want* the
  special file name conversion to happen.

- it is shorter to read and write.

- future calls to sys_wcstombs() will not incur unwanted conversion by
  accident (it is easy for unsuspecting programmers to assume that the
  function name "sys_wcstombs()" refers to a regular text conversion that
  has nothing to do with paths or filenames).

By keeping the name sys_wcstombs() (and not switching to
sys_wcstombs_path()), the following call sites are implicitly changed to
*exclude* the special path/file name conversion:

cygheap.h (get_drive):
	Cannot contain special characters

external.cc (cygwin_internal):
	Refers to user/domain names, not paths

fhandler_clipboard.cc (fhandler_dev_clipboard::read):
	Is not a path or file name but characters from the Windows
	clipboard

fhandler_console.cc: (dev_console::con_to_str):
	Is not a path or file name but characters from the console

fhandler_registry.cc (encode_regname):
	Is a registry key, not a path or filename

fhandler_registry.cc (multi_wcstombs):
	All call sites pass registry values, not paths or filenames

fhandler_registry.cc (fstat):
	Is a registry value, not a path or filename

fhandler_registry.cc (fill_filebuf):
	Is a registry value, not a path or filename

net.cc (get_ipv4fromreg):
	Is a registry value, not a path or filename

net.cc (get_friendlyname):
	Is a device name, not a path or filename

netdb.cc (open_system_file):
	Is from outside Cygwin

smallprint.cc (__small_vsprintf):
	Is a free text, not a path or filename

strfuncs.cc (strlwr):
	Should preserve the characters from the private page if there
	are any

strfuncs.cc (strupr):
	Should preserve the characters from the private page if there
	are any

uinfo.cc (cygheap_user::init):
	Refers to a user name, not a path or filename

uinfo.cc (pwdgrp::fetch_account_from_windows):
	Refers to value from outside Cygwin

By keeping the function name sys_wcstombs_alloc() (and not changing it to
sys_wcstombs_alloc_path()), the following call sites are implicitly
changed to *exclude* the special path/file name conversion:

ldap.cc (cyg_ldap::remap_uid):
	Refers to a user name, not a path or filename

ldap.cc (cyg_ldap::remap_gid):
	Refers to a group name, not a path or filename

pinfo.cc (_pinfo::cmdline):
	Refers to a command line from Windows, outside Cygwin

uinfo.cc (cygheap_user::env_logsrv):
	Is a server name, not a path or filename

uinfo.cc (cygheap_user::env_domain):
	Refers to the user/domain name, not a path or filename

uinfo.cc (cygheap_user::env_userprofile):
	Refers to Windows' idea of a path, outside Cygwin

uinfo.cc (cygheap_user::env_systemroot):
	Refers to Windows' idea of a path, outside Cygwin

uinfo.cc (fetch_from_description):
	Refers to values from outside of Cygwin

uinfo.cc (cygheap_pwdgrp::get_gecos):
	Refers to user/domain name and email address, not path nor filename

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

Author: dscho

winsup/cygwin/dcrt0.cc

@@ -957,9 +957,9 @@ dll_crt0_1 (void *)
   if (!__argc)
     {
       PWCHAR wline = GetCommandLineW ();
-      size_t size = sys_wcstombs_no_path (NULL, 0, wline) + 1;
+      size_t size = sys_wcstombs (NULL, 0, wline) + 1;
       char *line = (char *) alloca (size);
-      sys_wcstombs_no_path (line, size, wline);
+      sys_wcstombs (line, size, wline);
 
       /* Scan the command line and build argv.  Expand wildcards if not
 	 called from another cygwin process. */

winsup/cygwin/dtable.cc

@@ -1011,7 +1011,7 @@ handle_to_fn (HANDLE h, char *posix_fn)
       if (wcsncasecmp (w32, DEVICE_PREFIX, DEVICE_PREFIX_LEN) != 0
 	  || !QueryDosDeviceW (NULL, fnbuf, sizeof (fnbuf) / sizeof (WCHAR)))
 	{
-	  sys_wcstombs (posix_fn, NT_MAX_PATH, w32, w32len);
+	  sys_wcstombs_path (posix_fn, NT_MAX_PATH, w32, w32len);
 	  return false;
 	}
 

winsup/cygwin/environ.cc

@@ -929,7 +929,7 @@ win32env_to_cygenv (PWCHAR rawenv, bool posify)
      eventually want to use them).  */
   for (i = 0, w = rawenv; *w != L'\0'; w = wcschr (w, L'\0') + 1, i++)
     {
-      sys_wcstombs_alloc_no_path (&newp, HEAP_NOTHEAP, w);
+      sys_wcstombs_alloc (&newp, HEAP_NOTHEAP, w);
       if (i >= envc)
         envp = (char **) realloc (envp, (4 + (envc += 100)) * sizeof (char *));
       envp[i] = newp;
@@ -989,15 +989,15 @@ getwinenveq (const char *name, size_t namelen, int x)
   int totlen = GetEnvironmentVariableW (name0, valbuf, 32768);
   if (totlen > 0)
     {
-      totlen = sys_wcstombs_no_path (NULL, 0, valbuf) + 1;
+      totlen = sys_wcstombs (NULL, 0, valbuf) + 1;
       if (x == HEAP_1_STR)
 	totlen += namelen;
       else
 	namelen = 0;
       char *p = (char *) cmalloc_abort ((cygheap_types) x, totlen);
       if (namelen)
 	strcpy (p, name);
-      sys_wcstombs_no_path (p + namelen, totlen, valbuf);
+      sys_wcstombs (p + namelen, totlen, valbuf);
       debug_printf ("using value from GetEnvironmentVariable for '%W'", name0);
       return p;
     }
@@ -1155,7 +1155,7 @@ build_env (const char * const *envp, PWCHAR &envblock, int &envc,
 	  for (winnum = 0, var = cwinenv;
 	       *var;
 	       ++winnum, var = wcschr (var, L'\0') + 1)
-	    sys_wcstombs_alloc_no_path (&winenv[winnum], HEAP_NOTHEAP, var);
+	    sys_wcstombs_alloc (&winenv[winnum], HEAP_NOTHEAP, var);
 	}
       DestroyEnvironmentBlock (cwinenv);
       /* Eliminate variables which are already available in envp, as well as

winsup/cygwin/external.cc

@@ -92,7 +92,7 @@ fillout_pinfo (pid_t pid, int winpid)
 	  ep.rusage_self = p->rusage_self;
 	  ep.rusage_children = p->rusage_children;
 	  ep.progname[0] = '\0';
-	  sys_wcstombs(ep.progname, MAX_PATH, p->progname);
+	  sys_wcstombs_path (ep.progname, MAX_PATH, p->progname);
 	  ep.strace_mask = 0;
 	  ep.version = EXTERNAL_PINFO_VERSION;
 

winsup/cygwin/fhandler_disk_file.cc

@@ -2136,7 +2136,7 @@ fhandler_disk_file::readdir_helper (DIR *dir, dirent *de, DWORD w32_err,
 	  char *p = stpcpy (file, pc.get_posix ());
 	  if (p[-1] != '/')
 	    *p++ = '/';
-	  sys_wcstombs (p, NT_MAX_PATH - (p - file),
+	  sys_wcstombs_path (p, NT_MAX_PATH - (p - file),
 			fname->Buffer, fname->Length / sizeof (WCHAR));
 	  path_conv fpath (file, PC_SYM_NOFOLLOW);
 	  if (fpath.issymlink ())
@@ -2157,7 +2157,7 @@ fhandler_disk_file::readdir_helper (DIR *dir, dirent *de, DWORD w32_err,
 	}
     }
 
-  sys_wcstombs (de->d_name, NAME_MAX + 1, fname->Buffer,
+  sys_wcstombs_path (de->d_name, NAME_MAX + 1, fname->Buffer,
 		fname->Length / sizeof (WCHAR));
 
   /* Don't try to optimize relative to dir->__d_position.  On several

winsup/cygwin/fhandler_netdrive.cc

@@ -250,15 +250,15 @@ fhandler_netdrive::readdir (DIR *dir, dirent *de)
 	  tp.u_get (&ds);
 	  RtlInitUnicodeString (&ss, bs);
 	  RtlDowncaseUnicodeString (&ds, &ss, FALSE);
-	  sys_wcstombs (de->d_name, sizeof de->d_name,
+	  sys_wcstombs_path (de->d_name, sizeof de->d_name,
 			ds.Buffer, ds.Length / sizeof (WCHAR));
 	  de->d_ino = hash_path_name (get_ino (), de->d_name);
 	}
       else
 	{
-	  sys_wcstombs (de->d_name, sizeof de->d_name, bs);
+	  sys_wcstombs_path (de->d_name, sizeof de->d_name, bs);
 	  char *rpath = tp.c_get ();
-	  sys_wcstombs (rpath, NT_MAX_PATH, nro->lpRemoteName);
+	  sys_wcstombs_path (rpath, NT_MAX_PATH, nro->lpRemoteName);
 	  de->d_ino = readdir_get_ino (rpath, false);
 	  /* We can't trust remote inode numbers of only 32 bit.  That means,
 	     remote NT4 NTFS, as well as shares of Samba version < 3.0. */

winsup/cygwin/fhandler_process.cc

@@ -574,10 +574,10 @@ static off_t
 format_process_winexename (void *data, char *&destbuf)
 {
   _pinfo *p = (_pinfo *) data;
-  size_t len = sys_wcstombs (NULL, 0, p->progname);
+  size_t len = sys_wcstombs_path (NULL, 0, p->progname);
   destbuf = (char *) crealloc_abort (destbuf, len + 1);
   /* With trailing \0 for backward compat reasons. */
-  sys_wcstombs (destbuf, len + 1, p->progname);
+  sys_wcstombs_path (destbuf, len + 1, p->progname);
   return len;
 }
 
@@ -1052,7 +1052,7 @@ format_process_maps (void *data, char *&destbuf)
 		      drive_maps.fixup_if_match (msi->SectionFileName.Buffer);
 		  if (mount_table->conv_to_posix_path (dosname,
 						       posix_modname, 0))
-		    sys_wcstombs (posix_modname, NT_MAX_PATH, dosname);
+		    sys_wcstombs_path (posix_modname, NT_MAX_PATH, dosname);
 		  stat64 (posix_modname, &st);
 		}
 	      else if (!threads.fill_if_match (cur.abase, mb.Type,
@@ -1098,7 +1098,7 @@ format_process_stat (void *data, char *&destbuf)
   else
     {
       PWCHAR last_slash = wcsrchr (p->progname, L'\\');
-      sys_wcstombs (cmd, NAME_MAX + 1,
+      sys_wcstombs_path (cmd, NAME_MAX + 1,
 		    last_slash ? last_slash + 1 : p->progname);
       int len = strlen (cmd);
       if (len > 4)
@@ -1201,7 +1201,8 @@ format_process_status (void *data, char *&destbuf)
   size_t vmsize = 0, vmrss = 0, vmdata = 0, vmlib = 0, vmtext = 0, vmshare = 0;
 
   PWCHAR last_slash = wcsrchr (p->progname, L'\\');
-  sys_wcstombs (cmd, NAME_MAX + 1, last_slash ? last_slash + 1 : p->progname);
+  sys_wcstombs_path (cmd, NAME_MAX + 1,
+		  last_slash ? last_slash + 1 : p->progname);
   int len = strlen (cmd);
   if (len > 4)
     {

winsup/cygwin/fhandler_procsys.cc

@@ -236,10 +236,11 @@ fhandler_procsys::fill_filebuf ()
   NtClose (h);
   if (!NT_SUCCESS (status))
     goto unreadable;
-  len = sys_wcstombs (NULL, 0, target.Buffer, target.Length / sizeof (WCHAR));
+  len = sys_wcstombs_path (NULL, 0,
+		  target.Buffer, target.Length / sizeof (WCHAR));
   filebuf = (char *) crealloc_abort (filebuf, procsys_len + len + 1);
-  sys_wcstombs (fnamep = stpcpy (filebuf, procsys), len + 1, target.Buffer,
-		target.Length / sizeof (WCHAR));
+  sys_wcstombs_path (fnamep = stpcpy (filebuf, procsys), len + 1,
+		  target.Buffer, target.Length / sizeof (WCHAR));
   while ((fnamep = strchr (fnamep, '\\')))
     *fnamep = '/';
   return true;
@@ -377,8 +378,8 @@ fhandler_procsys::readdir (DIR *dir, dirent *de)
 	res = ENMFILE;
       else
 	{
-	  sys_wcstombs (de->d_name, NAME_MAX + 1, dbi->ObjectName.Buffer,
-			dbi->ObjectName.Length / sizeof (WCHAR));
+	  sys_wcstombs_path (de->d_name, NAME_MAX + 1, dbi->ObjectName.Buffer,
+			     dbi->ObjectName.Length / sizeof (WCHAR));
 	  de->d_ino = hash_path_name (get_ino (), de->d_name);
 	  if (RtlEqualUnicodeString (&dbi->ObjectTypeName, &ro_u_natdir, FALSE))
 	    de->d_type = DT_DIR;

winsup/cygwin/mount.cc

@@ -441,7 +441,7 @@ fs_info::update (PUNICODE_STRING upath, HANDLE in_vol)
     {
       /* The filesystem name is only used in fillout_mntent and only if
 	 the filesystem isn't one of the well-known filesystems anyway. */
-      sys_wcstombs (fsn, sizeof fsn, ffai_buf.ffai.FileSystemName,
+      sys_wcstombs_path (fsn, sizeof fsn, ffai_buf.ffai.FileSystemName,
 		    ffai_buf.ffai.FileSystemNameLength / sizeof (WCHAR));
       strlwr (fsn);
     }
@@ -468,7 +468,7 @@ mount_info::create_root_entry (const PWCHAR root)
  /* Create a default root dir derived from the location of the Cygwin DLL.
     The entry is immutable, unless the "override" option is given in /etc/fstab. */
   char native_root[PATH_MAX];
-  sys_wcstombs (native_root, PATH_MAX, root);
+  sys_wcstombs_path (native_root, PATH_MAX, root);
   assert (*native_root != '\0');
   if (add_item (native_root, "/",
 		MOUNT_SYSTEM | MOUNT_IMMUTABLE | MOUNT_AUTOMATIC | MOUNT_NOACL)
@@ -846,7 +846,7 @@ mount_info::conv_to_posix_path (PWCHAR src_path, char *posix_path,
     }
   tmp_pathbuf tp;
   char *buf = tp.c_get ();
-  sys_wcstombs (buf, NT_MAX_PATH, src_path);
+  sys_wcstombs_path (buf, NT_MAX_PATH, src_path);
   int ret = conv_to_posix_path (buf, posix_path, ccp_flags);
   if (changed)
     src_path[0] = L'C';
@@ -1177,7 +1177,7 @@ mount_info::from_fstab_line (char *line, bool user)
 	{
 	  tmp_pathbuf tp;
 	  char *mb_tmp = tp.c_get ();
-	  sys_wcstombs (mb_tmp, PATH_MAX, tmp);
+	  sys_wcstombs_path (mb_tmp, PATH_MAX, tmp);
 
 	  mount_flags |= MOUNT_USER_TEMP;
 	  int res = mount_table->add_item (mb_tmp, posix_path, mount_flags);

winsup/cygwin/nlsfuncs.cc

@@ -1606,7 +1606,7 @@ internal_setlocale ()
   if (w_path)
     {
       char *c_path = tp.c_get ();
-      sys_wcstombs (c_path, 32768, w_path);
+      sys_wcstombs_path (c_path, 32768, w_path);
       setenv ("PATH", c_path, 1);
     }
 }