KT-13482 "Loop can be replaced with stdlib operations" changes semantics

#KT-13482 Fixed

idea/src/org/jetbrains/kotlin/idea/intentions/loopToCallChain/result/ForEachTransformation.kt

@@ -17,9 +17,9 @@
 package org.jetbrains.kotlin.idea.intentions.loopToCallChain.result
 
 import org.jetbrains.kotlin.idea.intentions.loopToCallChain.*
-import org.jetbrains.kotlin.psi.KtCallableDeclaration
-import org.jetbrains.kotlin.psi.KtExpression
-import org.jetbrains.kotlin.psi.KtForExpression
+import org.jetbrains.kotlin.psi.*
+import org.jetbrains.kotlin.psi.KtPsiUtil.isAssignment
+import org.jetbrains.kotlin.psi.psiUtil.anyDescendantOfType
 
 class ForEachTransformation(
         loop: KtForExpression,
@@ -53,6 +53,11 @@ class ForEachTransformation(
             if (state.previousTransformations.isEmpty()) return null // do not suggest conversion to just ".forEach{}" or ".forEachIndexed{}"
 
             val statement = state.statements.singleOrNull() ?: return null
+
+            // check if contains assignment to non-qualified variable - in this case only use of lazy sequence is correct
+            if (!state.lazySequence
+                && statement.anyDescendantOfType<KtBinaryExpression> { isAssignment(it) && it.left is KtNameReferenceExpression }) return null
+
             //TODO: should we disallow it for complicated statements like loops, if, when?
             val transformation = ForEachTransformation(state.outerLoop, state.inputVariable, state.indexVariable, statement)
             return TransformationMatch.Result(transformation)

idea/testData/intentions/loopToCallChain/asSequenceOnly.kt

@@ -0,0 +1,14 @@
+// WITH_RUNTIME
+// IS_APPLICABLE: false
+// INTENTION_TEXT_2: "Replace with 'asSequence().filter{}.forEach{}'"
+fun getMaxLineWidth(lineCount: Int): Float {
+    var max_width = 0.0f
+    <caret>for (i in 0..lineCount - 1) {
+        if (getLineWidth(i) > max_width) {
+            max_width = getLineWidth(i)
+        }
+    }
+    return max_width
+}
+
+fun  getLineWidth(i: Int): Float = TODO()

idea/testData/intentions/loopToCallChain/asSequenceOnly.kt.after2

@@ -0,0 +1,13 @@
+// WITH_RUNTIME
+// IS_APPLICABLE: false
+// INTENTION_TEXT_2: "Replace with 'asSequence().filter{}.forEach{}'"
+fun getMaxLineWidth(lineCount: Int): Float {
+    var max_width = 0.0f
+    <caret>(0..lineCount - 1)
+            .asSequence()
+            .filter { getLineWidth(it) > max_width }
+            .forEach { max_width = getLineWidth(it) }
+    return max_width
+}
+
+fun  getLineWidth(i: Int): Float = TODO()

idea/tests/org/jetbrains/kotlin/idea/intentions/IntentionTest2Generated.java

@@ -131,6 +131,12 @@ public class IntentionTest2Generated extends AbstractIntentionTest2 {
         doTest(fileName);
     }
 
+    @TestMetadata("asSequenceOnly.kt")
+    public void testAsSequenceOnly() throws Exception {
+        String fileName = KotlinTestUtils.navigationMetadata("idea/testData/intentions/loopToCallChain/asSequenceOnly.kt");
+        doTest(fileName);
+    }
+
     @TestMetadata("assignFilter.kt")
     public void testAssignFilter() throws Exception {
         String fileName = KotlinTestUtils.navigationMetadata("idea/testData/intentions/loopToCallChain/assignFilter.kt");

idea/tests/org/jetbrains/kotlin/idea/intentions/IntentionTestGenerated.java

@@ -7291,6 +7291,12 @@ public class IntentionTestGenerated extends AbstractIntentionTest {
             doTest(fileName);
         }
 
+        @TestMetadata("asSequenceOnly.kt")
+        public void testAsSequenceOnly() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/intentions/loopToCallChain/asSequenceOnly.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("assignFilter.kt")
         public void testAssignFilter() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("idea/testData/intentions/loopToCallChain/assignFilter.kt");