Index: main/config.c
===================================================================
--- main/config.c	(revision 154022)
+++ main/config.c	(working copy)
@@ -1005,13 +1005,13 @@
 {
 	FILE *f = NULL;
 	int fd = -1;
-	char fn[256], fntmp[256];
+	char fn[256], fntmp[256], fnpath[256], *slashptr;
 	char date[256]="";
 	time_t t;
 	struct ast_variable *var;
 	struct ast_category *cat;
 	struct ast_comment *cmt;
-	struct stat s;
+	struct stat s, s2;
 	int blanklines = 0;
 	int stat_result = 0;
 
@@ -1022,6 +1022,16 @@
 		snprintf(fntmp, sizeof(fntmp), "%s/%s.XXXXXX", ast_config_AST_CONFIG_DIR, configfile);
 		snprintf(fn, sizeof(fn), "%s/%s", ast_config_AST_CONFIG_DIR, configfile);
 	}
+
+	ast_copy_string(fnpath, fn, sizeof(fnpath));
+	if ((slashptr = strrchr(fnpath, '/'))) {
+		*slashptr = '\0';
+	}
+	if (ast_lock_path(fnpath) != AST_LOCK_SUCCESS) {
+		ast_log(LOG_ERROR, "Unable to lock path '%s'\n", fnpath);
+		return -1;
+	}
+
 	time(&t);
 	ast_copy_string(date, ctime(&t), sizeof(date));
 	if ((fd = mkstemp(fntmp)) > 0 && (f = fdopen(fd, "w")) != NULL) {
@@ -1123,11 +1133,18 @@
 			ast_verbose(VERBOSE_PREFIX_2 "Unable to write %s (%s)", fn, strerror(errno));
 		if (fd > -1)
 			close(fd);
+		ast_unlock_path(fnpath);
 		return -1;
 	}
 	if (!(stat_result = stat(fn, &s))) {
 		fchmod(fd, s.st_mode);
+	} else {
+		ast_log(LOG_WARNING, "Unable to stat config file: %s: %s\n", fn, strerror(errno));
 	}
+	if (fstat(fd, &s2) || s2.st_size == 0) {
+		ast_log(LOG_ERROR, "Resulting file %s is of size 0.  This is a hard error.  I cannot continue.\n", fntmp);
+		stat_result = -1;
+	}
 	fclose(f);
 	if ((!stat_result && unlink(fn)) || link(fntmp, fn)) {
 		if (option_debug)
@@ -1135,9 +1152,11 @@
 		if (option_verbose > 1)
 			ast_verbose(VERBOSE_PREFIX_2 "Unable to write %s (%s)", fn, strerror(errno));
 		unlink(fntmp);
+		ast_unlock_path(fnpath);
 		return -1;
 	}
 	unlink(fntmp);
+	ast_unlock_path(fnpath);
 	return 0;
 }