From d634deea4ed7b018ece6cef6185abf98bb443338 Mon Sep 17 00:00:00 2001
From: Steve Loughran <stevel@cloudera.com>
Date: Mon, 6 Nov 2023 17:52:05 +0000
Subject: [PATCH] HADOOP-18487. Protobuf 2.5 removal part 2: stop exporting
 protobuf-2.5 (#6185)

Followup to the previous HADOOP-18487 patch: changes the scope of
protobuf-2.5 in hadoop-common and elsewhere from "compile" to "provided".

This means that protobuf-2.5 is
* No longer included in hadoop distributions
* No longer exported by hadoop common POM files
* No longer exported transitively by other hadoop modules.
* No longer listed in LICENSE-binary.

Contributed by Steve Loughran
---
 BUILDING.txt           | 24 +++++++++++++++---------
 LICENSE-binary         |  1 -
 hadoop-project/pom.xml |  4 ++--
 3 files changed, 17 insertions(+), 12 deletions(-)

diff --git a/BUILDING.txt b/BUILDING.txt
index 91d317ebe2..77561c5546 100644
--- a/BUILDING.txt
+++ b/BUILDING.txt
@@ -319,15 +319,11 @@ Controlling the redistribution of the protobuf-2.5 dependency
     the Hadoop codebase; alongside the move to Protobuf 3.x a private successor
     class, org.apache.hadoop.ipc.internal.ShadedProtobufHelper is now used.
 
-    The hadoop-common JAR still declares a dependency on protobuf-2.5, but this
-    is likely to change in the future. The maven scope of the dependency can be
-    set with the common.protobuf2.scope option.
-    It can be set to "provided" in a build:
-       -Dcommon.protobuf2.scope=provided
-    If this is done then protobuf-2.5.0.jar will no longer be exported as a dependency,
-    and will then be omitted from the share/hadoop/common/lib/ directory of
-    any Hadoop distribution built. Any application declaring a dependency on hadoop-commmon
-    will no longer get the dependency; if they need it then they must explicitly declare it:
+    The hadoop-common module no longer exports its compile-time dependency on
+    protobuf-2.5. Hadoop distributions no longer include it.
+    Any application declaring a dependency on hadoop-commmon will no longer get
+    the artifact added to their classpath.
+    If is still required, then they must explicitly declare it:
 
       <dependency>
         <groupId>com.google.protobuf</groupId>
@@ -335,6 +331,16 @@ Controlling the redistribution of the protobuf-2.5 dependency
         <version>2.5.0</version>
       </dependency>
 
+    In Hadoop builds the scope of the dependency can be set with the
+    option "common.protobuf2.scope".
+    This can be upgraded from "provided" to "compile" on the maven command line:
+
+           -Dcommon.protobuf2.scope=compile
+
+    If this is done then protobuf-2.5.0.jar will again be exported as a
+    hadoop-common dependency, and included in the share/hadoop/common/lib/
+    directory of any Hadoop distribution built.
+
 ----------------------------------------------------------------------------------
 Building components separately
 
diff --git a/LICENSE-binary b/LICENSE-binary
index 3a0e19c582..0ec5ee30f5 100644
--- a/LICENSE-binary
+++ b/LICENSE-binary
@@ -392,7 +392,6 @@ hadoop-tools/hadoop-sls/src/main/html/js/thirdparty/d3.v3.js
 hadoop-hdfs-project/hadoop-hdfs/src/main/webapps/static/d3-3.5.17.min.js
 leveldb v1.13
 
-com.google.protobuf:protobuf-java:2.5.0
 com.google.protobuf:protobuf-java:3.6.1
 com.google.re2j:re2j:1.1
 com.jcraft:jsch:0.1.54
diff --git a/hadoop-project/pom.xml b/hadoop-project/pom.xml
index 5b1c569d21..33e34a7d80 100644
--- a/hadoop-project/pom.xml
+++ b/hadoop-project/pom.xml
@@ -88,8 +88,8 @@
     <!-- This is used in hadoop-common for compilation only -->
     <protobuf.version>2.5.0</protobuf.version>
     <!-- Protobuf scope in hadoop common -->
-    <!-- set to "provided" and protobuf2 will no longer be exported as a dependency  -->
-    <common.protobuf2.scope>compile</common.protobuf2.scope>
+    <!-- set to "provided" so protobuf2 is no longer exported as a dependency  -->
+    <common.protobuf2.scope>provided</common.protobuf2.scope>
     <!-- Protobuf scope in other modules which explicitly import the libarary -->
     <transient.protobuf2.scope>${common.protobuf2.scope}</transient.protobuf2.scope>
     <!-- ProtocolBuffer version, actually used in Hadoop -->