Fix matching against one of multiple env-variables pointing to one JDK

pom.xml

@@ -146,4 +146,34 @@ under the License.
       </plugin>
     </plugins>
   </build>
+  <profiles>
+    <profile>
+      <id>run-its</id>
+      <build>
+        <plugins>
+          <plugin>
+            <groupId>org.codehaus.mojo</groupId>
+            <artifactId>build-helper-maven-plugin</artifactId>
+            <version>3.6.1</version>
+            <executions>
+              <execution>
+                <id>sanitize-java-home</id>
+                <goals>
+                  <goal>regex-property</goal>
+                </goals>
+                <!-- Prevent it-test failures on Windows due to interpretation of back-slashes in paths.-->
+                <configuration>
+                  <name>java.home.sanitized</name>
+                  <value>${java.home}</value>
+                  <regex>\\</regex>
+                  <replacement>/</replacement>
+                  <failIfNoMatch>false</failIfNoMatch>
+                </configuration>
+              </execution>
+            </executions>
+          </plugin>
+        </plugins>
+      </build>
+    </profile>
+  </profiles>
 </project>

src/it/select-jdk-env-multi/invoker.properties

@@ -0,0 +1,22 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+invoker.goals = compile
+# cannot run this IT with Maven 2 since required --toolchains option was added in 3.0-alpha-3: see MNG-3714
+invoker.maven.version = 3.0+
+invoker.environmentVariables.JAVA_X_HOME = ${java.home.sanitized}
+invoker.environmentVariables.JAVA_Y_HOME = ${java.home.sanitized}

src/it/select-jdk-env-multi/pom.xml

@@ -0,0 +1,54 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+Licensed to the Apache Software Foundation (ASF) under one
+or more contributor license agreements.  See the NOTICE file
+distributed with this work for additional information
+regarding copyright ownership.  The ASF licenses this file
+to you under the Apache License, Version 2.0 (the
+"License"); you may not use this file except in compliance
+with the License.  You may obtain a copy of the License at
+
+  http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing,
+software distributed under the License is distributed on an
+"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+KIND, either express or implied.  See the License for the
+specific language governing permissions and limitations
+under the License.
+-->
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+
+  <groupId>org.apache.maven.plugins.toolchains.its</groupId>
+  <artifactId>select-jdk-toolchain-range</artifactId>
+  <version>1.0-SNAPSHOT</version>
+  <packaging>jar</packaging>
+
+  <name>maven-toolchains-plugin IT: select jdk toolchain test with environment variable</name>
+  <description>Check that jdk toolchain can be selected when multiple environment variables are used</description>
+
+  <properties>
+    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+  </properties>
+
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-toolchains-plugin</artifactId>
+        <version>@project.version@</version>
+        <configuration>
+          <env>JAVA_X_HOME</env>
+        </configuration>
+        <executions>
+          <execution>
+            <goals>
+              <goal>select-jdk-toolchain</goal>
+            </goals>
+          </execution>
+        </executions>
+      </plugin>
+    </plugins>
+  </build>
+</project>

src/main/java/org/apache/maven/plugins/toolchain/jdk/SelectJdkToolchainMojo.java

@@ -255,7 +255,7 @@ private boolean matches(String key, String reqVal, String tcVal) {
             case VERSION:
                 return RequirementMatcherFactory.createVersionMatcher(tcVal).matches(reqVal);
             case ENV:
-                return reqVal.matches("(.*,|^)\\Q" + tcVal + "\\E(,.*|$)");
+                return tcVal.matches("(.*,|^)\\Q" + reqVal + "\\E(,.*|$)");
             default:
                 return RequirementMatcherFactory.createExactMatcher(tcVal).matches(reqVal);
         }