From 4155ef280867a6ccfe94d6f89cee4662ab24898f Mon Sep 17 00:00:00 2001
From: "Roger D. Peng [audrey]" <rpeng@jhsph.edu>
Date: Tue, 19 Aug 2008 09:33:43 -0400
Subject: [PATCH] Add a 'tryCatch' when modifying 'map0' in 'checkMap'

When there is a size change, we modify 'map' directly via the
'read_key_map' function.  But if there is an error at the C level then
'map' is left in an inconsistent state.  Therefore, in case of an error
we just return the original map (before modification).
---
 R/filehash-DB1.R | 26 +++++++++++++++++---------
 1 file changed, 17 insertions(+), 9 deletions(-)

diff --git a/R/filehash-DB1.R b/R/filehash-DB1.R
index 3d4e72a..4e79959 100644
--- a/R/filehash-DB1.R
+++ b/R/filehash-DB1.R
@@ -196,7 +196,7 @@ deleteLockFile <- function(name) {
         TRUE
 }
 
-######################################################################
+################################################################################
 ## Internal utilities
 
 filesize <- gotoEndPos
@@ -212,15 +212,23 @@ setMethod("checkMap", "filehashDB1",
                           old.size
                   })
                   size.change <- old.size != cur.size
-                  map.orig <- getMap(db)
-
-                  map <- if(is.null(map.orig))
-                          readKeyMap(filecon)
-                  else if(size.change)
-                          readKeyMap(filecon, map.orig, old.size)
+                  map <- getMap(db)
+                  map0 <- map
+
+                  if(is.null(map))
+                          map <- readKeyMap(filecon)
+                  else if(size.change) {
+                          ## Modify 'map.old' directly
+                          map <- tryCatch({
+                                  readKeyMap(filecon, map, old.size)
+                          }, error = function(err) {
+                                  message(conditionMessage(err))
+                                  map0
+                          })
+                  }
                   else
-                          map.orig
-                  if(!identical(map, map.orig)) {
+                          map <- map0
+                  if(!identical(map, map0)) {
                           db@meta$updatemap(map)
                           db@meta$updatesize(cur.size)
                   }
-- 
2.11.4.GIT