Ensure stdout/stderr are flushed when asking questions

Addresses FS#23492, where the question was shown without knowing what
one was answering to. Ensure we flush our output streams before printing
the question, and flush the stream on which we ask the question before
waiting for an answer.

Signed-off-by: Dan McGee <dan@archlinux.org>

src/pacman/util.c

@@ -878,6 +878,10 @@ static int question(short preset, char *fmt, va_list args)
 		stream = stderr;
 	}
 
+	/* ensure all text makes it to the screen before we prompt the user */
+	fflush(stdout);
+	fflush(stderr);
+
 	vfprintf(stream, fmt, args);
 
 	if(preset) {
@@ -891,6 +895,7 @@ static int question(short preset, char *fmt, va_list args)
 		return(preset);
 	}
 
+	fflush(stream);
 	if(fgets(response, sizeof(response), stdin)) {
 		strtrim(response);
 		if(strlen(response) == 0) {