Ant task: don't pass kotlin-runtime.jar to javac on "-no-stdlib"

ant/src/org/jetbrains/kotlin/ant/KotlinCompilerAdapter.java

@@ -98,12 +98,21 @@ public class KotlinCompilerAdapter extends Javac13 {
         // Javac13#execute passes everything in compileList to javac, which doesn't recognize .kt files
         compileList = filterOutKotlinSources(compileList);
 
+        addRuntimeToJavacClasspath(kotlinc);
+
+        return compileList.length == 0 || super.execute();
+    }
+
+    private void addRuntimeToJavacClasspath(@NotNull Kotlin2JvmTask kotlinc) {
+        for (String arg : kotlinc.getArgs()) {
+            // If "-no-stdlib" was specified explicitly, probably the user also wanted the javac classpath to not have it
+            if ("-no-stdlib".equals(arg)) return;
+        }
+
         if (compileClasspath == null) {
             compileClasspath = new Path(getProject());
         }
         compileClasspath.add(new Path(getProject(), KotlinAntTaskUtil.INSTANCE$.getRuntimeJar().getAbsolutePath()));
-
-        return compileList.length == 0 || super.execute();
     }
 
     private void checkAntVersion() {

compiler/testData/integration/ant/jvm/noStdlibForJavac/J.java

@@ -0,0 +1,5 @@
+package test;
+
+import kotlin.Unit;
+
+public class J {}

compiler/testData/integration/ant/jvm/noStdlibForJavac/build.log.expected

@@ -0,0 +1,21 @@
+OUT:
+Buildfile: [TestData]/build.xml
+
+build:
+    [mkdir] Created dir: [Temp]/classes
+    [javac] Compiling 1 source file to [Temp]/classes
+    [javac] Compiling [[TestData]] => [[Temp]/classes]
+    [javac] Running javac...
+    [javac] [TestData]/J.java:3: package kotlin does not exist
+    [javac] import kotlin.Unit;
+    [javac]              ^
+    [javac] 1 error
+
+ERR:
+
+BUILD FAILED
+[TestData]/build.xml:6: Compile failed; see the compiler error output for details.
+
+Total time: [time]
+
+Return code: 1

compiler/testData/integration/ant/jvm/noStdlibForJavac/build.xml

@@ -0,0 +1,12 @@
+<project name="Ant Task Test" default="build">
+    <taskdef resource="org/jetbrains/kotlin/ant/antlib.xml" classpath="${kotlin.lib}/kotlin-ant.jar"/>
+
+    <target name="build">
+        <mkdir dir="${temp}/classes"/>
+        <javac srcdir="${test.data}" destdir="${temp}/classes" includeantruntime="false">
+            <withKotlin>
+                <compilerarg value="-no-stdlib"/>
+            </withKotlin>
+        </javac>
+    </target>
+</project>

compiler/tests/org/jetbrains/kotlin/integration/AntTaskTestGenerated.java

@@ -59,6 +59,12 @@ public class AntTaskTestGenerated extends AbstractAntTaskTest {
         doTest(fileName);
     }
 
+    @TestMetadata("noStdlibForJavac")
+    public void testNoStdlibForJavac() throws Exception {
+        String fileName = JetTestUtils.navigationMetadata("compiler/testData/integration/ant/jvm/noStdlibForJavac/");
+        doTest(fileName);
+    }
+
     @TestMetadata("suppressWarnings")
     public void testSuppressWarnings() throws Exception {
         String fileName = JetTestUtils.navigationMetadata("compiler/testData/integration/ant/jvm/suppressWarnings/");