From 5c37134bf7aa192f2e62e81627c6e152c7d311d0 Mon Sep 17 00:00:00 2001
From: Dmitry Batkovich <dmitry.batkovich@jetbrains.com>
Date: Mon, 11 Jan 2016 14:33:59 +0300
Subject: [PATCH] type migration: don't migrate method qualifiers type if type
 parameters are assignable (example: IDEA-150178)

---
 .../TypeMigrationStatementProcessor.java      | 23 +++++++++++++++++--
 .../typeMigration/t17/after/Test.items        |  9 +-------
 .../typeMigration/t17/after/test.java         |  2 +-
 .../typeMigration/t93/after/Test.items        |  3 ---
 4 files changed, 23 insertions(+), 14 deletions(-)

diff --git a/java/java-impl/src/com/intellij/refactoring/typeMigration/TypeMigrationStatementProcessor.java b/java/java-impl/src/com/intellij/refactoring/typeMigration/TypeMigrationStatementProcessor.java
index a5c757d14b05..bfbb4cfe2b76 100644
--- a/java/java-impl/src/com/intellij/refactoring/typeMigration/TypeMigrationStatementProcessor.java
+++ b/java/java-impl/src/com/intellij/refactoring/typeMigration/TypeMigrationStatementProcessor.java
@@ -449,8 +449,8 @@ class TypeMigrationStatementProcessor extends JavaRecursiveElementVisitor {
         final PsiType qualifierType = qualifier.getType();
         if (qualifierType instanceof PsiClassType) {
           final PsiClassType.ClassResolveResult classResolveResult = ((PsiClassType)qualifierType).resolveGenerics();
-          final PsiType migrationType =
-              classResolveResult.getSubstitutor().substitute(evalSubstitutor.substitute(JavaPsiFacade.getElementFactory(myStatement.getProject()).createType(classResolveResult.getElement(), PsiSubstitutor.EMPTY)));
+          final PsiElementFactory elementFactory = JavaPsiFacade.getElementFactory(myStatement.getProject());
+          final PsiType migrationType = elementFactory.createType(classResolveResult.getElement(), composeIfNotAssignable(classResolveResult.getSubstitutor(), evalSubstitutor));
           myLabeler.migrateExpressionType(qualifier, migrationType, myStatement, migrationType.equals(qualifierType), true);
         }
       }
@@ -650,4 +650,23 @@ class TypeMigrationStatementProcessor extends JavaRecursiveElementVisitor {
     }
     return false;
   }
+
+  private static PsiSubstitutor composeIfNotAssignable(PsiSubstitutor actual, PsiSubstitutor required) {
+    if (actual == PsiSubstitutor.EMPTY) {
+      return required;
+    }
+    if (required == PsiSubstitutor.EMPTY) {
+      return actual;
+    }
+    PsiSubstitutor result = PsiSubstitutorImpl.createSubstitutor(actual.getSubstitutionMap());
+    for (Map.Entry<PsiTypeParameter, PsiType> e : required.getSubstitutionMap().entrySet()) {
+      final PsiTypeParameter typeParameter = e.getKey();
+      final PsiType requiredType = e.getValue();
+      final PsiType actualType = result.getSubstitutionMap().get(typeParameter);
+      if (requiredType != null && (actualType == null || !TypeConversionUtil.isAssignable(actualType, requiredType))) {
+        result = result.put(typeParameter, requiredType);
+      }
+    }
+    return result;
+  }
 }
diff --git a/java/typeMigration/testData/refactoring/typeMigration/t17/after/Test.items b/java/typeMigration/testData/refactoring/typeMigration/t17/after/Test.items
index aa0aa0551659..59b74e1b30bb 100644
--- a/java/typeMigration/testData/refactoring/typeMigration/t17/after/Test.items
+++ b/java/typeMigration/testData/refactoring/typeMigration/t17/after/Test.items
@@ -1,18 +1,11 @@
 Types:
 PsiField:f : B
-PsiMethodCallExpression:f.foo(s) : B
-PsiMethodCallExpression:s.add(f) : boolean
-PsiParameter:s : java.util.Set<B>
+PsiMethodCallExpression:f.foo(s) : A
 PsiReferenceExpression:f : B
 PsiReferenceExpression:f : B
-PsiReferenceExpression:s : java.util.Set<B>
-PsiReferenceExpression:s : java.util.Set<B>
 
 Conversions:
-f -> $
 f.foo(s) -> $
-s -> $
-s.add(f) -> $
 
 New expression type changes:
 Fails:
diff --git a/java/typeMigration/testData/refactoring/typeMigration/t17/after/test.java b/java/typeMigration/testData/refactoring/typeMigration/t17/after/test.java
index 73530057f21b..d90d101faed2 100644
--- a/java/typeMigration/testData/refactoring/typeMigration/t17/after/test.java
+++ b/java/typeMigration/testData/refactoring/typeMigration/t17/after/test.java
@@ -2,7 +2,7 @@ import java.util.*;
 class Test {
     B f;
 
-    A bar(Set<B> s) {
+    A bar(Set<A> s) {
         s.add(f);
         return f.foo(s);
     }
diff --git a/java/typeMigration/testData/refactoring/typeMigration/t93/after/Test.items b/java/typeMigration/testData/refactoring/typeMigration/t93/after/Test.items
index ea2fc9440478..aaa26f9139cb 100644
--- a/java/typeMigration/testData/refactoring/typeMigration/t93/after/Test.items
+++ b/java/typeMigration/testData/refactoring/typeMigration/t93/after/Test.items
@@ -1,11 +1,8 @@
 Types:
-PsiField:f : java.util.Map<java.lang.Boolean,java.lang.String>
 PsiParameter:b : boolean
 PsiReferenceExpression:b : boolean
-PsiReferenceExpression:f : java.util.Map<java.lang.Boolean,java.lang.String>
 
 Conversions:
-f -> $
 
 New expression type changes:
 Fails:
-- 
2.32.0