w32: Always use Unicode for console input and output.

* common/init.c (_init_common_subsystems) [W32]: Set the codepage to
UTF-8 for input and putput.  Switch gettext to UTF-8.
* g10/gpg.c (utf8_strings) [W32]: Make sure this is always set.
--

With this patch the former patch to use ReadConsoleW and WriteConsoleW
in ttyio.c are kind of superfluous because the ANSI version of these
functions are also able to read/write UTF-8 directly given the console
code page has been set correctly.  However, this seems to work only
with recent versions of Windows-10.

GnuPG-bug-id: 4365
(cherry picked from commit 8c41b8aac3efb78178fe1eaf52d8d1bbc44941a8)
Removed changes for "gpgconf --show-codepages" of the original patch.

common/init.c

@@ -202,6 +202,17 @@ _init_common_subsystems (gpg_err_source_t errsource, int *argcp, char ***argvp)
   parse_std_file_handles (argcp, argvp);
 #endif
 
+#ifdef HAVE_W32_SYSTEM
+  /* We want gettext to always output UTF-8 and we put the console in
+   * utf-8 mode.  */
+  gettext_use_utf8 (1);
+  if (!SetConsoleCP (CP_UTF8) || !SetConsoleOutputCP (CP_UTF8))
+    {
+      log_info ("SetConsoleCP failed: %s\n", w32_strerror (-1));
+      log_info ("Warning: Garbled console data possible\n");
+    }
+#endif
+
   /* Access the standard estreams as early as possible.  If we don't
      do this the original stdio streams may have been closed when
      _es_get_std_stream is first use and in turn it would connect to

doc/gpg.texi

@@ -1532,13 +1532,14 @@ not used).
 
 @item --display-charset @var{name}
 @opindex display-charset
-Set the name of the native character set. This is used to convert
+Set the name of the native character set. This is used to convert some
-some informational strings like user IDs to the proper UTF-8 encoding.
+informational strings like user IDs to the proper UTF-8 encoding.
 Note that this has nothing to do with the character set of data to be
-encrypted or signed; GnuPG does not recode user-supplied data. If
+encrypted or signed; GnuPG does not recode user-supplied data. If this
-this option is not used, the default character set is determined from
+option is not used, the default character set is determined from the
-the current locale. A verbosity level of 3 shows the chosen set.
+current locale. A verbosity level of 3 shows the chosen set.  This
-Valid values for @var{name} are:
+option should not be used on Windows.  Valid values for @var{name}
+are:
 
 @table @asis
 
@@ -1575,6 +1576,12 @@ encoded in the character set as specified by
 arguments. Both options may be used multiple times.
 This option should not be used in an option file.
 
+This option has no effect on Windows.  There the internal used UTF-8
+encoding is translated for console input and output.  The command line
+arguments are expected as Unicode and translated to UTF-8.  Thus when
+calling this program from another, make sure to use the Unicode
+version of CreateProcess.
+
 @anchor{gpg-option --options}
 @item --options @var{file}
 @opindex options

g10/gpg.c

@@ -970,7 +970,13 @@ static struct debug_flags_s debug_flags [] =
 
 int g10_errors_seen = 0;
 
-static int utf8_strings = 0;
+static int utf8_strings =
+#ifdef HAVE_W32_SYSTEM
+  1
+#else
+  0
+#endif
+  ;
 static int maybe_setuid = 1;
 
 static char *build_list( const char *text, char letter,
@@ -3308,7 +3314,11 @@ main (int argc, char **argv)
 	    opt.verify_options&=~VERIFY_SHOW_NOTATIONS;
 	    break;
 	  case oUtf8Strings: utf8_strings = 1; break;
-	  case oNoUtf8Strings: utf8_strings = 0; break;
+	  case oNoUtf8Strings:
+#ifdef HAVE_W32_SYSTEM
+            utf8_strings = 0;
+#endif
+            break;
 	  case oDisableCipherAlgo:
             {
               int algo = string_to_cipher_algo (pargs.r.ret_str);