From d39df59044f9d240f16c12809431278e49d3779f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Adri=C3=A1n=20Musante?=
 <38815440+adrianmusante@users.noreply.github.com>
Date: Mon, 17 Aug 2020 16:38:14 -0300
Subject: [PATCH] JENKINS-52264 The variable "=" is removed when the exec
 command is executed (#219)

---
 .../docker/workflow/WithContainerStep.java    |  5 +-
 .../workflow/WithContainerStepTest.java       | 68 +++++++++++++++++++
 2 files changed, 71 insertions(+), 2 deletions(-)

diff --git a/src/main/java/org/jenkinsci/plugins/docker/workflow/WithContainerStep.java b/src/main/java/org/jenkinsci/plugins/docker/workflow/WithContainerStep.java
index 41f4910b3..ebbfd68a3 100644
--- a/src/main/java/org/jenkinsci/plugins/docker/workflow/WithContainerStep.java
+++ b/src/main/java/org/jenkinsci/plugins/docker/workflow/WithContainerStep.java
@@ -286,10 +286,11 @@ private static class Decorator extends LauncherDecorator implements Serializable
                     Set<String> envReduced = new TreeSet<String>(Arrays.asList(starter.envs()));
                     envReduced.removeAll(Arrays.asList(envHost));
 
-                    // Remove PATH during `exec` as well.
+                    // Remove PATH or invalid variable during `exec` as well.
                     Iterator<String> it = envReduced.iterator();
                     while (it.hasNext()) {
-                        if (it.next().startsWith("PATH=")) {
+                        final String envVar = it.next();
+                        if (envVar.startsWith("PATH=") || "=".equals(envVar.trim())) {
                             it.remove();
                         }
                     }
diff --git a/src/test/java/org/jenkinsci/plugins/docker/workflow/WithContainerStepTest.java b/src/test/java/org/jenkinsci/plugins/docker/workflow/WithContainerStepTest.java
index c5ddf141a..4c9a97447 100644
--- a/src/test/java/org/jenkinsci/plugins/docker/workflow/WithContainerStepTest.java
+++ b/src/test/java/org/jenkinsci/plugins/docker/workflow/WithContainerStepTest.java
@@ -36,6 +36,7 @@
 import hudson.util.ArgumentListBuilder;
 import hudson.util.Secret;
 import java.io.File;
+import java.util.Collection;
 import java.util.Collections;
 import java.util.logging.Level;
 
@@ -387,4 +388,71 @@ private static final class Execution extends SynchronousNonBlockingStepExecution
         }
     }
 
+    @Issue("JENKINS-52264")
+    @Test public void removeInvalidEnvVars() throws IOException {
+        story.then(r -> {
+            DockerTestUtil.assumeDocker();
+            WorkflowJob p = r.jenkins.createProject(WorkflowJob.class, "p");
+            p.setDefinition(new CpsFlowDefinition(
+                "node {\n" +
+                    "  withDockerContainer('ubuntu') {\n" +
+                    "    removeInvalidEnvVarsStep([]) \n" + //without envVars to overwrite
+                    "    removeInvalidEnvVarsStep([\"other=only_valid_value\"]) \n" + //only valid envVar
+                    "    removeInvalidEnvVarsStep([\"=\", \"other=with_empty_var\"]) \n" + //with empty variable
+                    "    removeInvalidEnvVarsStep([\"PATH=ignored_value\", \"other=with_path\"]) \n" + //with PATH variable
+                    "    removeInvalidEnvVarsStep([\"=\", \"PATH=ignored_value\", \"other=with_path_and_empty\"]) \n" + //both invalid variables
+                    "  }\n" +
+                    "}", true));
+            WorkflowRun b = story.j.assertBuildStatusSuccess(p.scheduleBuild2(0));
+            story.j.assertLogContains("working with empty environment.", b);
+            story.j.assertLogContains("only_valid_value", b);
+            story.j.assertLogContains("with_empty_var", b);
+            story.j.assertLogContains("with_path", b);
+            story.j.assertLogContains("with_path_and_empty", b);
+            story.j.assertLogNotContains("ignored_value", b);
+        });
+    }
+    public static final class RemoveInvalidEnvVarsStep extends Step {
+        public final Collection<String> envVars;
+        @DataBoundConstructor public RemoveInvalidEnvVarsStep(Collection<String> envVars) {
+            this.envVars = envVars;
+        }
+        @Override public StepExecution start(StepContext context) throws Exception {
+            return new Execution(context, envVars);
+        }
+        private static final class Execution extends SynchronousNonBlockingStepExecution<Void> {
+            private final Collection<String> envVars;
+            Execution(StepContext context, Collection<String> envVars) {
+                super(context);
+                this.envVars = envVars;
+            }
+            @Override protected Void run() throws Exception {
+                Launcher.ProcStarter ps = getContext().get(Launcher.class).launch();
+                ps.envs(envVars.toArray(new String[0]));
+                ArgumentListBuilder args = new ArgumentListBuilder("sh", "-c");
+                if(envVars.isEmpty()) {
+                    args.add("echo working with empty environment.");
+                } else {
+                    args.add("printenv other && printenv PATH");
+                }
+                final int exitCode = ps
+                    .cmds(args)
+                    .stdout(getContext().get(TaskListener.class))
+                    .join();
+                if (exitCode != 0) {
+                    throw new IOException("failed to run exec command with vars: "+envVars);
+                }
+                return null;
+            }
+        }
+        @TestExtension("removeInvalidEnvVars") public static final class DescriptorImpl extends StepDescriptor {
+            @Override public String getFunctionName() {
+                return "removeInvalidEnvVarsStep";
+            }
+            @Override public Set<? extends Class<?>> getRequiredContext() {
+                return ImmutableSet.of(Launcher.class, TaskListener.class);
+            }
+        }
+    }
+
 }