mingw: really handle SIGINT

Previously, we did not install any handler for Ctrl+C, but now we really
want to because the MSYS2 runtime learned the trick to call the
ConsoleCtrlHandler when Ctrl+C was pressed.

With this, hitting Ctrl+C while `git log` is running will only terminate
the Git process, but not the pager. This finally matches the behavior on
Linux and on macOS.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/compat/mingw.c b/compat/mingw.c
index 44c6305..41e055f 100644
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -3623,7 +3623,14 @@ static void adjust_symlink_flags(void)
 		symlink_file_flags |= 2;
 		symlink_directory_flags |= 2;
 	}
+}
 
+static BOOL WINAPI handle_ctrl_c(DWORD ctrl_type)
+{
+	if (ctrl_type != CTRL_C_EVENT)
+		return FALSE; /* we did not handle this */
+	mingw_raise(SIGINT);
+	return TRUE; /* we did handle this */
 }
 
 #ifdef _MSC_VER
@@ -3660,6 +3667,8 @@ int wmain(int argc, const wchar_t **wargv)
 #endif
 #endif
 
+	SetConsoleCtrlHandler(handle_ctrl_c, TRUE);
+
 	maybe_redirect_std_handles();
 	adjust_symlink_flags();