From a4edc46a5f21d51278f83bda548290b68f2bb0ad Mon Sep 17 00:00:00 2001
From: Andrew Johnson <anj@aps.anl.gov>
Date: Wed, 20 Mar 2013 16:53:10 -0500
Subject: [PATCH] dbStatic: Allow empty DB & DBD files

They used to cause a Syntax error with a bad context string.
---
 documentation/RELEASE_NOTES.html | 7 +++++++
 src/dbStatic/dbYacc.y            | 8 +++++++-
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/documentation/RELEASE_NOTES.html b/documentation/RELEASE_NOTES.html
index 98c9415b1..f62a502c7 100644
--- a/documentation/RELEASE_NOTES.html
+++ b/documentation/RELEASE_NOTES.html
@@ -13,6 +13,13 @@
 
 <!-- Insert new items immediately below here ... -->
 
+<h4>Allow empty database files</h4>
+
+<p>The IOC used to report an error if dbLoadRecords or dbLoadDatabase was asked
+to load an empty file or one containing just whitespace and/or comments. Such
+files are now permitted, simplifying the task of automated database generation
+programs which might discover they have nothing to output.</p>
+
 <h4>High-Resolution Time Provider on MacOS</h4>
 
 <p>MacOS does not provide the clock_gettime() API with CLOCK_REALTIME that other
diff --git a/src/dbStatic/dbYacc.y b/src/dbStatic/dbYacc.y
index b61ab26ea..b8cc9b4cf 100644
--- a/src/dbStatic/dbYacc.y
+++ b/src/dbStatic/dbYacc.y
@@ -31,7 +31,13 @@ static int yyAbort = 0;
 
 %%
 
-database:	database database_item | database_item;
+database:	/* empty */
+	|	database_item_list
+	;
+
+database_item_list:	database_item_list database_item
+	|	database_item
+	;
 
 database_item:	include
 	|	path