PY-25234 Fix ordering for imports resolved into binary skeletons of stdlib

Previously, we used the priority of the binary skeletons directory
itself, thus placing them in a wrong THIRD_PARTY group.

python/src/com/jetbrains/python/codeInsight/imports/ImportFromExistingAction.java

@@ -39,6 +39,7 @@ import com.intellij.ui.SimpleColoredComponent;
 import com.intellij.ui.SimpleTextAttributes;
 import com.intellij.ui.components.JBList;
 import com.intellij.util.Consumer;
+import com.intellij.util.ObjectUtils;
 import com.jetbrains.python.PyBundle;
 import com.jetbrains.python.psi.*;
 import com.jetbrains.python.psi.impl.PyPsiUtils;
@@ -48,6 +49,8 @@ import javax.swing.*;
 import java.awt.*;
 import java.util.List;
 
+import static com.jetbrains.python.psi.PyUtil.as;
+
 /**
  * Turns an unqualified unresolved identifier into qualified and resolvable.
  *
@@ -148,7 +151,9 @@ public class ImportFromExistingAction implements QuestionAction {
   private void addImportStatement(ImportCandidateHolder item) {
     final Project project = myTarget.getProject();
     final PyElementGenerator gen = PyElementGenerator.getInstance(project);
-    AddImportHelper.ImportPriority priority = AddImportHelper.getImportPriority(myTarget, item.getFile());
+
+    final PsiFileSystemItem filesystemAnchor = ObjectUtils.chooseNotNull(as(item.getImportable(), PsiFileSystemItem.class), item.getFile());
+    AddImportHelper.ImportPriority priority = AddImportHelper.getImportPriority(myTarget, filesystemAnchor);
     PsiFile file = myTarget.getContainingFile();
     InjectedLanguageManager manager = InjectedLanguageManager.getInstance(project);
     if (manager.isInjectedFragment(file)) {

python/testData/quickFixes/PyAddImportQuickFixTest/skeletonStdlibModule/main.py

@@ -0,0 +1,5 @@
+import re
+
+import mod
+
+print(re, <error descr="Unresolved reference 'sys'">s<caret>ys</error>, mod)

python/testData/quickFixes/PyAddImportQuickFixTest/skeletonStdlibModule/main_after.py

@@ -0,0 +1,6 @@
+import re
+import sys
+
+import mod
+
+print(re, sys, mod)

python/testSrc/com/jetbrains/python/quickFixes/PyAddImportQuickFixTest.java

@@ -55,15 +55,18 @@ public class PyAddImportQuickFixTest extends PyQuickFixTestCase {
     doMultiFileAutoImportTest("Import this name");
   }
 
+  public void testSkeletonStdlibModule() {
+    doMultiFileAutoImportTest("Import 'sys'");
+  }
+
   private void doMultiFileAutoImportTest(@NotNull String hintPrefix) {
     myFixture.copyDirectoryToProject(getTestName(true), "");
     myFixture.enableInspections(PyUnresolvedReferencesInspection.class);
-    final String entryPoint = "main";
-    myFixture.configureByFile(entryPoint + ".py");
+    myFixture.configureByFile("main.py");
     myFixture.checkHighlighting(true, false, false);
-    IntentionAction intention = myFixture.findSingleIntention(hintPrefix);
 
+    final IntentionAction intention = myFixture.findSingleIntention(hintPrefix);
     myFixture.launchAction(intention);
-    myFixture.checkResultByFile(getTestName(true) + "/" + entryPoint + "_after.py", true);
+    myFixture.checkResultByFile(getTestName(true) + "/main_after.py", true);
   }
 }