===================================================================
RCS file: /cvs/mandoc/mandocdb.c,v
retrieving revision 1.249
retrieving revision 1.254
diff -u -p -r1.249 -r1.254
--- mandoc/mandocdb.c	2017/05/05 15:17:32	1.249
+++ mandoc/mandocdb.c	2017/08/26 12:59:17	1.254
@@ -1,4 +1,4 @@
-/*	$Id: mandocdb.c,v 1.249 2017/05/05 15:17:32 schwarze Exp $ */
+/*	$Id: mandocdb.c,v 1.254 2017/08/26 12:59:17 schwarze Exp $ */
 /*
  * Copyright (c) 2011, 2012 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2011-2017 Ingo Schwarze <schwarze@openbsd.org>
@@ -420,7 +420,8 @@ mandocdb(int argc, char *argv[])
 
 	exitcode = (int)MANDOCLEVEL_OK;
 	mchars_alloc();
-	mp = mparse_alloc(mparse_options, MANDOCLEVEL_BADARG, NULL, NULL);
+	mp = mparse_alloc(mparse_options, MANDOCERR_MAX, NULL,
+	    MANDOC_OS_OTHER, NULL);
 	mandoc_ohash_init(&mpages, 6, offsetof(struct mpage, inodev));
 	mandoc_ohash_init(&mlinks, 6, offsetof(struct mlink, file));
 
@@ -2118,10 +2119,27 @@ dbprune(struct dba *dba)
 static void
 dbwrite(struct dba *dba)
 {
-	char		 tfn[32];
+	char		 tfn[33];
 	int		 status;
 	pid_t		 child;
 
+	/*
+	 * Do not write empty databases, and delete existing ones
+	 * when makewhatis -u causes them to become empty.
+	 */
+
+	dba_array_start(dba->pages);
+	if (dba_array_next(dba->pages) == NULL) {
+		if (unlink(MANDOC_DB) == -1 && errno != ENOENT)
+			say(MANDOC_DB, "&unlink");
+		return;
+	}
+
+	/*
+	 * Build the database in a temporary file,
+	 * then atomically move it into place.
+	 */
+
 	if (dba_write(MANDOC_DB "~", dba) != -1) {
 		if (rename(MANDOC_DB "~", MANDOC_DB) == -1) {
 			exitcode = (int)MANDOCLEVEL_SYSERR;
@@ -2131,6 +2149,11 @@ dbwrite(struct dba *dba)
 		return;
 	}
 
+	/*
+	 * We lack write permission and cannot replace the database
+	 * file, but let's at least check whether the data changed.
+	 */
+
 	(void)strlcpy(tfn, "/tmp/mandocdb.XXXXXXXX", sizeof(tfn));
 	if (mkdtemp(tfn) == NULL) {
 		exitcode = (int)MANDOCLEVEL_SYSERR;
@@ -2170,26 +2193,9 @@ dbwrite(struct dba *dba)
 	}
 
 out:
+	unlink(tfn);
 	*strrchr(tfn, '/') = '\0';
-	switch (child = fork()) {
-	case -1:
-		exitcode = (int)MANDOCLEVEL_SYSERR;
-		say("", "&fork rm");
-		return;
-	case 0:
-		execlp("rm", "rm", "-rf", tfn, (char *)NULL);
-		say("", "&exec rm");
-		exit((int)MANDOCLEVEL_SYSERR);
-	default:
-		break;
-	}
-	if (waitpid(child, &status, 0) == -1) {
-		exitcode = (int)MANDOCLEVEL_SYSERR;
-		say("", "&wait rm");
-	} else if (WIFSIGNALED(status) || WEXITSTATUS(status)) {
-		exitcode = (int)MANDOCLEVEL_SYSERR;
-		say("", "%s: Cannot remove temporary directory", tfn);
-	}
+	rmdir(tfn);
 }
 
 static int