branches/KDE/4.6/kdelibs/kdecore/util

[Michael Pyne]

SVN commit 1214946 by mpyne:

Backport "Fully clear cache metadata in clearInternal()" to 4.6.

KSharedDataCache uses the clearInternal() method to reset the cache, which is
used if corruption is detected, and when directed through
KSharedDataCache::clear().  For whatever reason I thought that simply setting
the "first page" pointer for each possible index entry would be sufficient, but
that is not the case at all, as various methods which go through the cache
entries also check things such as the use count, last access time, etc.

Assuming no other errors (:-/) this should be the cause of bug 260309. (The
exact sequence would be a KSharedDataCache user runs ::clear(), later adds some
entries that invoke removeUsedPages(), and removeUsedPages() goes through *all*
index entries, including ones that appear to be in use since their use count is
>0, but their first page is still invalid). Easiest way to invoke this bug I've
found is to simply run "plasmoidviewer clock" at a konsole.

This should fix the annoying bug 260309 just in time for KDE Platform 4.6. I'm
CC-ing release team so that there are no surprises, but I have hopefully
demonstrated enough of the issue to prove that this patch is at least "more
correct" than previous behavior.

It is possible that this was also the proximate cause of the Plasma crashes
when changing the system time for Daylight Savings (which I worked around with
the error message you've been seeing for months), bug 253795.

FIXED-IN:4.6
BUG:260309
CCBUG:253795
CCMAIL:release-team at kde.org


 M  +5 -0      kshareddatacache.cpp  


--- branches/KDE/4.6/kdelibs/kdecore/util/kshareddatacache.cpp #1214945:1214946
@@ -437,6 +437,11 @@
         IndexTableEntry *indices = indexTable();
         for (uint i = 0; i < indexTableSize(); ++i) {
             indices[i].firstPage = -1;
+            indices[i].useCount = 0;
+            indices[i].fileNameHash = 0;
+            indices[i].totalItemSize = 0;
+            indices[i].addTime = 0;
+            indices[i].lastUsedTime = 0;
         }
     }