fix stub-ast mismatch caused by broken import list

plus add a test for mismatch in IDEA-169118

java/java-psi-impl/src/com/intellij/lang/java/parser/FileParser.java

@@ -147,37 +147,41 @@ public class FileParser {
   private Pair<PsiBuilder.Marker, Boolean> parseImportList(PsiBuilder builder, Predicate<PsiBuilder> stopper) {
     PsiBuilder.Marker list = builder.mark();
 
-    IElementType tokenType = builder.getTokenType();
-    boolean isEmpty = tokenType != JavaTokenType.IMPORT_KEYWORD && tokenType != JavaTokenType.SEMICOLON;
-    if (!isEmpty) {
-      PsiBuilder.Marker invalidElements = null;
-      while (!builder.eof()) {
-        if (stopper.test(builder)) {
-          break;
-        }
-        else if (builder.getTokenType() == JavaTokenType.SEMICOLON) {
-          builder.advanceLexer();
-          continue;
-        }
-
-        final PsiBuilder.Marker statement = parseImportStatement(builder);
-        if (statement != null) {
-          if (invalidElements != null) {
-            invalidElements.errorBefore(JavaErrorMessages.message("unexpected.token"), statement);
-            invalidElements = null;
-          }
-          continue;
-        }
-
-        if (invalidElements == null) {
-          invalidElements = builder.mark();
-        }
+    boolean isEmpty = true;
+    PsiBuilder.Marker invalidElements = null;
+    while (!builder.eof()) {
+      if (stopper.test(builder)) {
+        break;
+      }
+      else if (builder.getTokenType() == JavaTokenType.SEMICOLON) {
         builder.advanceLexer();
+        continue;
       }
 
-      if (invalidElements != null) {
-        invalidElements.error(JavaErrorMessages.message("unexpected.token"));
+      final PsiBuilder.Marker statement = parseImportStatement(builder);
+      if (statement != null) {
+        isEmpty = false;
+        if (invalidElements != null) {
+          invalidElements.errorBefore(JavaErrorMessages.message("unexpected.token"), statement);
+          invalidElements = null;
+        }
+        continue;
       }
+
+      if (invalidElements == null) {
+        invalidElements = builder.mark();
+      }
+      builder.advanceLexer();
+    }
+
+    if (invalidElements != null) {
+      invalidElements.error(JavaErrorMessages.message("unexpected.token"));
+    }
+
+    if (isEmpty) {
+      PsiBuilder.Marker precede = list.precede();
+      list.rollbackTo();
+      list = precede;
     }
 
     done(list, JavaElementType.IMPORT_LIST);

java/java-tests/testData/psi/parser-partial/files/ImportBrokenFromBeginning.txt

@@ -0,0 +1,13 @@
+PsiJavaFile:ImportBrokenFromBeginning.java
+  PsiImportList
+    PsiErrorElement:Unexpected token
+      PsiIdentifier:xx('xx')
+    PsiWhiteSpace(' ')
+    PsiImportStatement
+      PsiKeyword:import('import')
+      PsiWhiteSpace(' ')
+      PsiJavaCodeReferenceElement:a
+        PsiIdentifier:a('a')
+        PsiReferenceParameterList
+          <empty list>
+      PsiJavaToken:SEMICOLON(';')

java/java-tests/testSrc/com/intellij/java/parser/partial/FileParserTest.java

@@ -38,6 +38,7 @@ public class FileParserTest extends JavaParsingTestCase {
   public void testUnclosedImport1() { doParserTest("import java.awt.*"); }
   public void testUnclosedImport2() { doParserTest("import java.awt."); }
   public void testUnclosedImport3() { doParserTest("import static a"); }
+  public void testImportBrokenFromBeginning() { doParserTest("xx import a;"); }
 
   public void testExtraSemicolons() {
     doParserTest(

java/java-tests/testSrc/com/intellij/java/psi/JavaStubsTest.groovy

@@ -19,15 +19,21 @@ import com.intellij.codeInsight.AnnotationTargetUtil
 import com.intellij.codeInspection.dataFlow.ControlFlowAnalyzer
 import com.intellij.openapi.application.ApplicationManager
 import com.intellij.openapi.application.ReadAction
+import com.intellij.openapi.command.WriteCommandAction
 import com.intellij.psi.PsiAnnotationMethod
 import com.intellij.psi.PsiClassType
+import com.intellij.psi.PsiDocumentManager
+import com.intellij.psi.PsiJavaFile
 import com.intellij.psi.PsiReferenceExpression
+import com.intellij.psi.SyntaxTraverser
 import com.intellij.psi.impl.source.PsiClassImpl
 import com.intellij.psi.impl.source.PsiFileImpl
+import com.intellij.psi.impl.source.tree.TreeUtil
 import com.intellij.psi.search.GlobalSearchScope
 import com.intellij.psi.search.searches.AnnotatedElementsSearch
 import com.intellij.psi.search.searches.ClassInheritorsSearch
 import com.intellij.psi.util.PsiUtil
+import com.intellij.testFramework.PsiTestUtil
 import com.intellij.testFramework.fixtures.LightCodeInsightFixtureTestCase
 
 import java.util.concurrent.Callable
@@ -173,4 +179,29 @@ import java.lang.annotation.*;
     assert !((PsiFileImpl) cls.containingFile).contentsLoaded
   }
 
+  void "test breaking and adding import does not cause stub AST mismatch"() {
+    def file = myFixture.addFileToProject("a.java", "import foo.*; import bar.*; class Foo {}") as PsiJavaFile
+    def another = myFixture.addClass("package zoo; public class Another {}")
+    WriteCommandAction.runWriteCommandAction(project) { 
+      file.viewProvider.document.insertString(file.text.indexOf('import'), 'x')
+      PsiDocumentManager.getInstance(project).commitAllDocuments()
+      file.importClass(another)
+    }
+    PsiTestUtil.checkStubsMatchText(file)
+  }
+
+  void "test adding type before method call does not cause stub AST mismatch"() {
+    def file = myFixture.addFileToProject("a.java", """
+class Foo {
+  void foo() {
+    something();
+    call();
+  }
+}
+""") as PsiJavaFile
+    WriteCommandAction.runWriteCommandAction(project) { 
+      file.viewProvider.document.insertString(file.text.indexOf('call'), 'char ')
+      PsiTestUtil.checkStubsMatchText(file)
+    }
+  }
 }