fix collecting completion stats for methods with argument suggestions

ensure that we don't change the tracked document range when starting live template

java/java-impl/src/com/intellij/codeInsight/completion/JavaMethodCallElement.java

@@ -210,7 +210,6 @@ public class JavaMethodCallElement extends LookupItem<PsiMethod> implements Type
                                             PsiExpressionList argList,
                                             TextRange argRange) {
     Template template = TemplateManager.getInstance(method.getProject()).createTemplate("", "");
-    template.addTextSegment(argList.getText().substring(0, caretOffset - argRange.getStartOffset()));
     PsiParameter[] parameters = method.getParameterList().getParameters();
     for (int i = 0; i < parameters.length; i++) {
       if (i > 0) {
@@ -254,7 +253,7 @@ public class JavaMethodCallElement extends LookupItem<PsiMethod> implements Type
 
     Template template = createArgTemplate(method, caretOffset, argList, argRange);
 
-    context.getDocument().deleteString(argRange.getStartOffset(), argRange.getEndOffset());
+    context.getDocument().deleteString(caretOffset, argRange.getEndOffset());
     TemplateManager.getInstance(method.getProject()).startTemplate(editor, template);
 
     TemplateState templateState = TemplateManagerImpl.getTemplateState(editor);

java/java-tests/testData/codeInsight/completion/signature/CollectStatisticsOnMethods.java

@@ -0,0 +1,8 @@
+class A {
+    {
+        tes<caret>
+    }
+
+    void test2(int a);
+    void test1(int a);
+}

java/java-tests/testData/codeInsight/completion/signature/CollectStatisticsOnMethods_after.java

@@ -0,0 +1,8 @@
+class A {
+    {
+        test2(2)<caret>;
+    }
+
+    void test2(int a);
+    void test1(int a);
+}

java/java-tests/testSrc/com/intellij/codeInsight/completion/SignatureCompletionTest.groovy

@@ -19,6 +19,9 @@ import com.intellij.JavaTestUtil
 import com.intellij.codeInsight.template.impl.TemplateManagerImpl
 import com.intellij.openapi.util.registry.Registry
 import com.intellij.psi.PsiMethod
+import com.intellij.psi.statistics.StatisticsManager
+import com.intellij.psi.statistics.impl.StatisticsManagerImpl
+
 /**
  * @author peter
  */
@@ -84,4 +87,16 @@ class SignatureCompletionTest extends LightFixtureCompletionTestCase {
     checkResult()
   }
 
+  void testCollectStatisticsOnMethods() {
+    ((StatisticsManagerImpl)StatisticsManager.instance).enableStatistics(testRootDisposable)
+    configureByTestName()
+    myFixture.assertPreferredCompletionItems 0, 'test1', 'test2'
+    myFixture.lookup.currentItem = myFixture.lookupElements[1]
+    myFixture.type('\n2\n')
+    checkResult()
+    myFixture.type(';\ntes')
+    myFixture.completeBasic()
+    myFixture.assertPreferredCompletionItems 0, 'test2', 'test1'
+  }
+
 }

platform/lang-impl/src/com/intellij/codeInsight/completion/StatisticsUpdate.kt

@@ -70,7 +70,9 @@ class StatisticsUpdate
 
     val document = context.document
     val startOffset = context.startOffset
-    val tailOffset = context.editor.caretModel.offset
+    val tailOffset =
+      if (context.editor.selectionModel.hasSelection()) context.editor.selectionModel.selectionStart
+      else context.editor.caretModel.offset
     if (startOffset < 0 || tailOffset <= startOffset) {
       return
     }