fix(import): Skip findImport and createPackage if necessary. Fixes …

…#759

src/main/java/spoon/support/compiler/jdt/ReferenceBuilder.java

@@ -249,19 +249,24 @@ CtReference getDeclaringReferenceFromImports(char[] expectedName) {
 						this.jdtTreeBuilder.getContextBuilder().ignoreComputeImports = false;
 						return typeReference;
 					} else {
+						PackageBinding packageBinding = null;
 						char[][] chars = CharOperation.subarray(anImport.getImportName(), 0, anImport.getImportName().length - 1);
-						Binding someBinding = this.jdtTreeBuilder.getContextBuilder().compilationunitdeclaration.scope.findImport(chars, false, false);
-						PackageBinding packageBinding;
-						if (someBinding != null && someBinding.isValidBinding() && someBinding instanceof PackageBinding) {
-							packageBinding = (PackageBinding) someBinding;
-						} else {
-							packageBinding = this.jdtTreeBuilder.getContextBuilder().compilationunitdeclaration.scope.environment.createPackage(chars);
-							if (packageBinding == null) {
-								// Big crisis here. We are already in noclasspath mode but JDT doesn't support always
-								// creation of a package in this mode. So, if we are in this brace, we make the job of JDT...
-								packageBinding = new PackageBinding(chars, null, this.jdtTreeBuilder.getContextBuilder().compilationunitdeclaration.scope.environment);
+						// `findImport(chars, false, false);` and `createPackage(chars)` require
+						// an array with a minimum length of 1 and throw an
+						// ArrayIndexOutOfBoundsException if `chars.length == 0`. Fixes #759.
+						if (chars.length > 0) {
+							Binding someBinding = this.jdtTreeBuilder.getContextBuilder().compilationunitdeclaration.scope.findImport(chars, false, false);
+							if (someBinding != null && someBinding.isValidBinding() && someBinding instanceof PackageBinding) {
+								packageBinding = (PackageBinding) someBinding;
+							} else {
+								packageBinding = this.jdtTreeBuilder.getContextBuilder().compilationunitdeclaration.scope.environment.createPackage(chars);
 							}
 						}
+						if (packageBinding == null) {
+							// Big crisis here. We are already in noclasspath mode but JDT doesn't support always
+							// creation of a package in this mode. So, if we are in this brace, we make the job of JDT...
+							packageBinding = new PackageBinding(chars, null, this.jdtTreeBuilder.getContextBuilder().compilationunitdeclaration.scope.environment);
+						}
 						return getPackageReference(packageBinding);
 					}
 				}

src/test/java/spoon/test/imports/ImportAndExtendWithPackageNameTest.java

@@ -0,0 +1,32 @@
+package spoon.test.imports;
+
+import org.junit.Assert;
+import org.junit.Test;
+import spoon.Launcher;
+import spoon.reflect.declaration.CtType;
+import spoon.reflect.reference.CtTypeReference;
+
+import java.util.Collection;
+
+public class ImportAndExtendWithPackageNameTest {
+
+    private static final String inputResource =
+            "./src/test/resources/import-resources/ImportAndExtendWithPackageName.java";
+
+    @Test
+    public void testBuildModel() {
+        final Launcher runLaunch = new Launcher();
+        runLaunch.getEnvironment().setNoClasspath(true);
+        runLaunch.addInputResource(inputResource);
+        runLaunch.buildModel();
+
+        final Collection<CtType<?>> types = runLaunch.getModel().getAllTypes();
+        Assert.assertSame(1, types.size());
+
+        final CtType type = types.iterator().next();
+        Assert.assertEquals("ImportAndExtendWithPackageName", type.getSimpleName());
+
+        final CtTypeReference superClass = type.getSuperclass();
+        Assert.assertEquals("LLkParser", superClass.getSimpleName());
+    }
+}

src/test/resources/import-resources/ImportAndExtendWithPackageName.java

@@ -0,0 +1,5 @@
+import antlr.*;
+
+public class ImportAndExtendWithPackageName extends antlr.LLkParser {
+    public static void main(final String[] args) {}
+}