Merge Debian's patch 466_fflush-prompt

* libmisc/Makefile.am, lib/prototypes.h, libmisc/yesno.c, src/grpck.c,
	src/pwck.c: move yes_or_no() from grpck/pwck to a separate
	libmisc/yesno.c (with a read_only argument).
	* libmisc/fields.c, libmisc/yesno.c: Make sure stdout is flushed before
	reading the user's answer.

libmisc/yesno.c

@@ -0,0 +1,75 @@
+/*
+ * Copyright 1992 - 1994, Julianne Frances Haugh
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of Julianne F. Haugh nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY JULIE HAUGH AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL JULIE HAUGH OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/*
+ * Common code for yes/no prompting
+ *
+ * Used by pwck.c and grpck.c
+ */
+
+#include "config.h"
+
+#ident "$Id$"
+
+#include <stdio.h>
+#include "prototypes.h"
+
+/*
+ * yes_or_no - get answer to question from the user
+ *
+ *	It returns 0 if no.
+ *
+ *	If the read_only flag is set, it will print No, and will return 0.
+ */
+int yes_or_no (int read_only)
+{
+	char buf[80];
+
+	/*
+	 * In read-only mode all questions are answered "no".
+	 */
+	if (read_only) {
+		printf (_("No\n"));
+		return 0;
+	}
+
+	/*
+	 * Typically, there's a prompt on stdout, sometimes unflushed.
+	 */
+	fflush (stdout);
+
+	/*
+	 * Get a line and see what the first character is.
+	 */
+	/* TODO: use gettext */
+	if (fgets (buf, sizeof buf, stdin))
+		return buf[0] == 'y' || buf[0] == 'Y';
+
+	return 0;
+}