===================================================================
RCS file: /cvs/mandoc/mandocdb.c,v
retrieving revision 1.49.2.2
retrieving revision 1.49.2.4
diff -u -p -r1.49.2.2 -r1.49.2.4
--- mandoc/mandocdb.c	2013/09/17 22:48:53	1.49.2.2
+++ mandoc/mandocdb.c	2013/09/17 23:12:21	1.49.2.4
@@ -1,4 +1,4 @@
-/*	$Id: mandocdb.c,v 1.49.2.2 2013/09/17 22:48:53 schwarze Exp $ */
+/*	$Id: mandocdb.c,v 1.49.2.4 2013/09/17 23:12:21 schwarze Exp $ */
 /*
  * Copyright (c) 2011, 2012 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2011, 2012 Ingo Schwarze <schwarze@openbsd.org>
@@ -299,7 +299,7 @@ main(int argc, char *argv[])
 	int		 ch, i, flags;
 	DB		*hash; /* temporary keyword hashtable */
 	BTREEINFO	 info; /* btree configuration */
-	size_t		 sz1, sz2;
+	size_t		 sz1, sz2, ipath;
 	struct buf	 buf, /* keyword buffer */
 			 dbuf; /* description buffer */
 	struct of	*of; /* list of files for processing */
@@ -482,7 +482,7 @@ main(int argc, char *argv[])
 	} else
 		manpath_parse(&dirs, dir, NULL, NULL);
 
-	for (i = 0; i < dirs.sz; i++) {
+	for (ipath = 0; ipath < dirs.sz; ipath++) {
 
 		/*
 		 * Go to the root of the respective manual tree.
@@ -490,25 +490,44 @@ main(int argc, char *argv[])
 		 * They are indexed relative to the root.
 		 */
 
-		if (-1 == chdir(dirs.paths[i])) {
-			perror(dirs.paths[i]);
+		if (-1 == chdir(dirs.paths[ipath])) {
+			perror(dirs.paths[ipath]);
 			exit((int)MANDOCLEVEL_SYSERR);
 		}
 
-		strlcpy(mdb.dbn, MANDOC_DB, PATH_MAX);
-		strlcpy(mdb.idxn, MANDOC_IDX, PATH_MAX);
+		/* Create a new database in two temporary files. */
 
-		flags = O_CREAT | O_TRUNC | O_RDWR;
-		mdb.db = dbopen(mdb.dbn, flags, 0644, DB_BTREE, &info);
-		mdb.idx = dbopen(mdb.idxn, flags, 0644, DB_RECNO, NULL);
-
-		if (NULL == mdb.db) {
-			perror(mdb.dbn);
-			exit((int)MANDOCLEVEL_SYSERR);
-		} else if (NULL == mdb.idx) {
-			perror(mdb.idxn);
-			exit((int)MANDOCLEVEL_SYSERR);
+		flags = O_CREAT | O_EXCL | O_RDWR;
+		while (NULL == mdb.db) {
+			strlcpy(mdb.dbn, MANDOC_DB, PATH_MAX);
+			strlcat(mdb.dbn, ".XXXXXXXXXX", PATH_MAX);
+			if (NULL == mktemp(mdb.dbn)) {
+				perror(mdb.dbn);
+				exit((int)MANDOCLEVEL_SYSERR);
+			}
+			mdb.db = dbopen(mdb.dbn, flags, 0644,
+					DB_BTREE, &info);
+			if (NULL == mdb.db && EEXIST != errno) {
+				perror(mdb.dbn);
+				exit((int)MANDOCLEVEL_SYSERR);
+			}
 		}
+		while (NULL == mdb.idx) {
+			strlcpy(mdb.idxn, MANDOC_IDX, PATH_MAX);
+			strlcat(mdb.idxn, ".XXXXXXXXXX", PATH_MAX);
+			if (NULL == mktemp(mdb.idxn)) {
+				perror(mdb.idxn);
+				unlink(mdb.dbn);
+				exit((int)MANDOCLEVEL_SYSERR);
+			}
+			mdb.idx = dbopen(mdb.idxn, flags, 0644,
+					DB_RECNO, NULL);
+			if (NULL == mdb.idx && EEXIST != errno) {
+				perror(mdb.idxn);
+				unlink(mdb.dbn);
+				exit((int)MANDOCLEVEL_SYSERR);
+			}
+		}
 
 		/*
 		 * Search for manuals and fill the new database.
@@ -527,6 +546,26 @@ main(int argc, char *argv[])
 		(*mdb.idx->close)(mdb.idx);
 		mdb.db = NULL;
 		mdb.idx = NULL;
+
+		/*
+		 * Replace the old database with the new one.
+		 * This is not perfectly atomic,
+		 * but i cannot think of a better way.
+		 */
+
+		if (-1 == rename(mdb.dbn, MANDOC_DB)) {
+			perror(MANDOC_DB);
+			unlink(mdb.dbn);
+			unlink(mdb.idxn);
+			exit((int)MANDOCLEVEL_SYSERR);
+		}
+		if (-1 == rename(mdb.idxn, MANDOC_IDX)) {
+			perror(MANDOC_IDX);
+			unlink(MANDOC_DB);
+			unlink(MANDOC_IDX);
+			unlink(mdb.idxn);
+			exit((int)MANDOCLEVEL_SYSERR);
+		}
 	}
 
 out: