From 4acc7862421a6d16cea6481212ec730d6dcaec5f Mon Sep 17 00:00:00 2001
From: Dmitry Cheryasov <Dmitry.Cheryasov@jetbrains.com>
Date: Fri, 23 May 2008 17:07:37 +0400
Subject: [PATCH] Transitive resolution (when an imported name is re-exported).

---
 .../jetbrains/python/psi/impl/PyFileImpl.java | 19 +++++++++++++++++++
 .../transitiveImport/TransitiveImport.py      |  3 +++
 .../multiFile/transitiveImport/channel.py     |  1 +
 .../multiFile/transitiveImport/source.py      |  1 +
 .../python/PyMultiFileResolveTest.java        |  6 ++++++
 5 files changed, 30 insertions(+)
 create mode 100644 python/testData/resolve/multiFile/transitiveImport/TransitiveImport.py
 create mode 100644 python/testData/resolve/multiFile/transitiveImport/channel.py
 create mode 100644 python/testData/resolve/multiFile/transitiveImport/source.py

diff --git a/python/src/com/jetbrains/python/psi/impl/PyFileImpl.java b/python/src/com/jetbrains/python/psi/impl/PyFileImpl.java
index 6c67c7f20d74..94405a00e083 100644
--- a/python/src/com/jetbrains/python/psi/impl/PyFileImpl.java
+++ b/python/src/com/jetbrains/python/psi/impl/PyFileImpl.java
@@ -87,6 +87,11 @@ public class PyFileImpl extends PsiFileBase implements PyFile {
       if (!processor.execute(e, substitutor)) return false;
     }
 
+    for(PyFromImportStatement e: getFromImports()) {
+      if (e == lastParent) continue;
+      if (!e.processDeclarations(processor, substitutor, null, this)) return false;
+    }
+
     // if we're in a stmt (not place itself), try buitins:
     if (lastParent != null) {
       final String fileName = getName();
@@ -147,6 +152,20 @@ public class PyFileImpl extends PsiFileBase implements PyFile {
     }
     return ret;
   }
+  
+  public List<PyFromImportStatement> getFromImports() {
+    final List<PyFromImportStatement> result = new ArrayList<PyFromImportStatement>();
+    accept(new PyRecursiveElementVisitor() {
+      public void visitPyElement(final PyElement node) {
+        super.visitPyElement(node);
+        if (PyFromImportStatement.class.isInstance(node)) {
+          //noinspection unchecked
+          result.add((PyFromImportStatement)node);
+        }
+      }
+    });
+    return result;
+  }
 
   private <T> List<T> getTopLevelItems(final IElementType elementType, final Class itemClass) {
     final List<T> result = new ArrayList<T>();
diff --git a/python/testData/resolve/multiFile/transitiveImport/TransitiveImport.py b/python/testData/resolve/multiFile/transitiveImport/TransitiveImport.py
new file mode 100644
index 000000000000..0a90b3a600e5
--- /dev/null
+++ b/python/testData/resolve/multiFile/transitiveImport/TransitiveImport.py
@@ -0,0 +1,3 @@
+from channel import * # token must pass through
+print(token)
+#     <ref>
\ No newline at end of file
diff --git a/python/testData/resolve/multiFile/transitiveImport/channel.py b/python/testData/resolve/multiFile/transitiveImport/channel.py
new file mode 100644
index 000000000000..7e9f3af36e9f
--- /dev/null
+++ b/python/testData/resolve/multiFile/transitiveImport/channel.py
@@ -0,0 +1 @@
+from source import token # this re-exports token
\ No newline at end of file
diff --git a/python/testData/resolve/multiFile/transitiveImport/source.py b/python/testData/resolve/multiFile/transitiveImport/source.py
new file mode 100644
index 000000000000..41011d58c253
--- /dev/null
+++ b/python/testData/resolve/multiFile/transitiveImport/source.py
@@ -0,0 +1 @@
+token = 'Yes' # an exported name
\ No newline at end of file
diff --git a/python/testSrc/com/jetbrains/python/PyMultiFileResolveTest.java b/python/testSrc/com/jetbrains/python/PyMultiFileResolveTest.java
index 57a77f095439..19994af68329 100644
--- a/python/testSrc/com/jetbrains/python/PyMultiFileResolveTest.java
+++ b/python/testSrc/com/jetbrains/python/PyMultiFileResolveTest.java
@@ -8,6 +8,7 @@ import com.intellij.psi.*;
 import com.intellij.testFramework.PsiTestUtil;
 import com.jetbrains.python.psi.PyFile;
 import com.jetbrains.python.psi.PyFunction;
+import com.jetbrains.python.psi.PyTargetExpression;
 
 /**
  * @author yole
@@ -78,6 +79,11 @@ public class PyMultiFileResolveTest extends CodeInsightTestCase {
     assertTrue(element instanceof PyFunction);
   }
 
+  public void testTransitiveImport() throws Exception {
+    PsiElement element = doResolve();
+    assertTrue(element instanceof PyTargetExpression);
+  }
+
   private PsiElement doResolve() throws Exception {
     String testName = getTestName(true);
     String fileName = getTestName(false) + ".py";