Fix latent bug in ser_windows_send_break

The ClearCommBreak documentation says:

    If the function fails, the return value is zero.

ser_windows_send_break inverts this check.  This has never been
noticed because the caller doesn't check the result.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30770

diff --git a/gdb/ser-mingw.c b/gdb/ser-mingw.c
index c0aa5d8d0b9a0aa73be4fae361ba951f97aa92ab..806f3999385bff4089eb86b0193303db3227ec08 100644 (file)
--- a/gdb/ser-mingw.c
+++ b/gdb/ser-mingw.c
@@ -137,7 +137,7 @@ ser_windows_send_break (struct serial *scb)
   /* Delay for 250 milliseconds.  */
   Sleep (250);
 
-  if (ClearCommBreak (h))
+  if (ClearCommBreak (h) == 0)
     return -1;
 
   return 0;