From 0e272c233d050961fe79b94f333668b900d4fbbe Mon Sep 17 00:00:00 2001
From: Brandon Williams <brandonwilliams@apache.org>
Date: Wed, 27 Aug 2014 10:08:18 -0500
Subject: [PATCH 1/2] Add ability to detect unofficial openjdk builds.

Patch by brandonwilliams, reviewed by enigmacurry for CASSANDRA-7799
---
 conf/cassandra-env.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/conf/cassandra-env.sh b/conf/cassandra-env.sh
index c4c8bd59ba..354442691c 100644
--- a/conf/cassandra-env.sh
+++ b/conf/cassandra-env.sh
@@ -90,7 +90,7 @@ calculate_heap_sizes()
 
 java_ver_output=`"${JAVA:-java}" -version 2>&1`
 
-jvmver=`echo "$java_ver_output" | grep 'java version' | awk -F'"' 'NR==1 {print $2}'`
+jvmver=`echo "$java_ver_output" | grep '[openjdk|java] version' | awk -F'"' 'NR==1 {print $2}'`
 JVM_VERSION=${jvmver%_*}
 JVM_PATCH_VERSION=${jvmver#*_}
 

From 36ecc69cbf3cc3734cf0602c60f101de95032a44 Mon Sep 17 00:00:00 2001
From: Aleksey Yeschenko <aleksey@apache.org>
Date: Thu, 28 Aug 2014 16:30:23 +0300
Subject: [PATCH 2/2] Forbid re-adding dropped counter columns

patch by Aleksey Yeschenko; reviewed by Jonathan Ellis for
CASSANDRA-7831
---
 CHANGES.txt                                                   | 1 +
 .../apache/cassandra/cql3/statements/AlterTableStatement.java | 4 ++++
 2 files changed, 5 insertions(+)

diff --git a/CHANGES.txt b/CHANGES.txt
index abdd56141a..20874ac253 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -1,4 +1,5 @@
 2.0.11:
+ * Forbid re-adding dropped counter columns (CASSANDRA-7831)
  * Fix CFMetaData#isThriftCompatible() for PK-only tables (CASSANDRA-7832)
  * Always reject inequality on the partition key without token()
    (CASSANDRA-7722)
diff --git a/src/java/org/apache/cassandra/cql3/statements/AlterTableStatement.java b/src/java/org/apache/cassandra/cql3/statements/AlterTableStatement.java
index dfcd601145..698c8b8a66 100644
--- a/src/java/org/apache/cassandra/cql3/statements/AlterTableStatement.java
+++ b/src/java/org/apache/cassandra/cql3/statements/AlterTableStatement.java
@@ -109,6 +109,10 @@ public class AlterTableStatement extends SchemaAlteringStatement
                     }
                 }
 
+                // Cannot re-add a dropped counter column. See #7831.
+                if (meta.getDefaultValidator().isCommutative() && meta.getDroppedColumns().containsKey(columnName.key))
+                    throw new InvalidRequestException(String.format("Cannot re-add previously dropped counter column %s", columnName));
+
                 AbstractType<?> type = validator.getType();
                 if (type instanceof CollectionType)
                 {