SOLR-12434: Fix standalone mode 'bin/solr config' to not pass in empty -z ZK_HOST param; revert accidental ZK_HOST definition in solr.in.cmd

solr/bin/solr

@@ -940,7 +940,13 @@ if [[ "$SCRIPT_CMD" == "config" ]]; then
       esac
     done
   fi
-  run_tool config -zkHost "$ZK_HOST" -scheme "$SOLR_URL_SCHEME" "${CONFIG_PARAMS[@]}"
+  if [[ -n "$ZK_HOST" ]]; then
+    CONFIG_PARAMS+=("-z" "$ZK_HOST")
+  fi
+  if [[ -n "$SOLR_URL_SCHEME" ]]; then
+    CONFIG_PARAMS+=("-scheme" "$SOLR_URL_SCHEME")
+  fi
+  run_tool config "${CONFIG_PARAMS[@]}"
   exit $?
 fi
 

solr/bin/solr.cmd

@@ -1426,10 +1426,13 @@ SHIFT
 goto parse_config_args
 
 :run_config
+IF NOT "!ZK_HOST!"=="" SET "CONFIG_ARGS=!CONFIG_ARGS! -z !ZK_HOST!"
+IF NOT "!SOLR_URL_SCHEME!"=="" SET "CONFIG_ARGS=!CONFIG_ARGS! -scheme !SOLR_URL_SCHEME!"
+
 "%JAVA%" %SOLR_SSL_OPTS% %AUTHC_OPTS% %SOLR_ZK_CREDS_AND_ACLS% -Dsolr.install.dir="%SOLR_TIP%" ^
   -Dlog4j.configurationFile="file:%DEFAULT_SERVER_DIR%\scripts\cloud-scripts\log4j2.xml" ^
   -classpath "%DEFAULT_SERVER_DIR%\solr-webapp\webapp\WEB-INF\lib\*;%DEFAULT_SERVER_DIR%\lib\ext\*" ^
-  org.apache.solr.util.SolrCLI config -zkHost !ZK_HOST! -scheme !SOLR_URL_SCHEME! !CONFIG_ARGS!
+  org.apache.solr.util.SolrCLI config !CONFIG_ARGS!
 if errorlevel 1 (
    exit /b 1
 )

solr/bin/solr.in.cmd

@@ -39,7 +39,7 @@ REM set GC_TUNE=-XX:NewRatio=3 -XX:SurvivorRatio=4     etc.
 REM Set the ZooKeeper connection string if using an external ZooKeeper ensemble
 REM e.g. host1:2181,host2:2181/chroot
 REM Leave empty if not using SolrCloud
-set ZK_HOST=localhost:2181
+REM set ZK_HOST=
 
 REM Set the ZooKeeper client timeout (for SolrCloud mode)
 REM set ZK_CLIENT_TIMEOUT=15000