win32: add support for the euro currency symbol

The euro currency symbol was added to some OEM code pages.  See:

   https://www.aivosto.com/articles/charsets-codepages-dos.html

Add a configuration option (enabled by default) to support this.
When enabled:

- The read_key() function requests wide character key events.  This
  allows the euro symbol to be entered regardless of the console OEM
  code page, though it needs to be available in the ANSI code page.

- Conversions between OEM and ANSI code pages in winansi.c are
  modified to work around a bug in the Microsoft routines.

- If the OEM code page is 850 when BusyBox starts it's changed to
  858.  This is the only currently supported OEM code page.

Also, the shell read builtin is modified to use read_key() whenever
input is being taken from the console.

1 files changed, 9 insertions, 0 deletions

diff --git a/Config.in b/Config.in
index 5bd98aa23..0318a6aff 100644
--- a/Config.in
+++ b/Config.in
@@ -454,6 +454,15 @@ config FEATURE_ICON_ALL
 
 endchoice
 
+config FEATURE_EURO
+        bool "Support the euro currency symbol (0.5 kb)"
+        default y
+        depends on PLATFORM_MINGW32
+        help
+        Support the entry and display of the euro currency symbol.  This
+        requires the OEM code page to be 858.  If the OEM code page of
+        the console is 850 when BusyBox starts it's changed to 858.
+
 comment 'Build Options'
 
 config STATIC