Index: database/database.4.0.mysql
===================================================================
RCS file: /cvs/drupal/drupal/database/Attic/database.4.0.mysql,v
retrieving revision 1.1.2.2
diff -u -p -r1.1.2.2 database.4.0.mysql
--- database/database.4.0.mysql	5 Dec 2006 13:11:08 -0000	1.1.2.2
+++ database/database.4.0.mysql	19 Dec 2006 14:13:00 -0000
@@ -161,7 +161,7 @@ CREATE TABLE boxes (
 --
 
 CREATE TABLE cache (
-  cid varchar(255) NOT NULL default '',
+  cid varchar(255) BINARY NOT NULL default '',
   data longblob,
   expire int(11) NOT NULL default '0',
   created int(11) NOT NULL default '0',
Index: database/database.4.1.mysql
===================================================================
RCS file: /cvs/drupal/drupal/database/Attic/database.4.1.mysql,v
retrieving revision 1.1.2.2
diff -u -p -r1.1.2.2 database.4.1.mysql
--- database/database.4.1.mysql	5 Dec 2006 13:11:09 -0000	1.1.2.2
+++ database/database.4.1.mysql	19 Dec 2006 14:12:52 -0000
@@ -172,7 +172,7 @@ DEFAULT CHARACTER SET utf8;
 --
 
 CREATE TABLE cache (
-  cid varchar(255) NOT NULL default '',
+  cid varchar(255) BINARY NOT NULL default '',
   data longblob,
   expire int(11) NOT NULL default '0',
   created int(11) NOT NULL default '0',
Index: database/updates.inc
===================================================================
RCS file: /cvs/drupal/drupal/database/Attic/updates.inc,v
retrieving revision 1.224.2.7
diff -u -p -r1.224.2.7 updates.inc
--- database/updates.inc	5 Dec 2006 13:11:09 -0000	1.224.2.7
+++ database/updates.inc	19 Dec 2006 14:18:18 -0000
@@ -2013,3 +2013,17 @@ function system_update_182() {
 
   return $ret;
 }
+
+/**
+ * Cid matching by MySQL should be case-sensitive.
+ */
+function system_update_183() {
+  $ret = array();
+  switch ($GLOBALS['db_type']) {
+    case 'mysql':
+    case 'mysqli':
+      $ret[] = update_sql("ALTER TABLE {cache} CHANGE cid cid varchar(255) BINARY NOT NULL default ''");
+      break;
+  }
+  return $ret;
+}