winansi: allow alternative screen buffer to be disabled

The alternative console screen buffer (used by less and vi) doesn't
work in Wine.

Setting the environment variable BB_ALT_BUFFER to 0 causes a screen
reset instead.

1 files changed, 7 insertions, 0 deletions

diff --git a/win32/winansi.c b/win32/winansi.c
index fd0de8656..c13d021d2 100644
--- a/win32/winansi.c
+++ b/win32/winansi.c
@@ -110,8 +110,15 @@ static HANDLE dup_handle(HANDLE h)
 static void use_alt_buffer(int flag)
 {
         static HANDLE console_orig = INVALID_HANDLE_VALUE;
+        const char *var;
         HANDLE console, h;
 
+        var = getenv("BB_ALT_BUFFER");
+        if (var && strcmp(var, "0") == 0) {
+                reset_screen();
+                return;
+        }
+
         if (flag) {
                 SECURITY_ATTRIBUTES sa;
                 CONSOLE_SCREEN_BUFFER_INFO sbi;