"Replace 'when' with 'if'" intention: do not suggest if 'when' subject is variable declaration

#KT-35528 Fixed

idea/src/org/jetbrains/kotlin/idea/intentions/branchedTransformations/intentions/WhenToIfIntention.kt

@@ -11,10 +11,7 @@ import com.intellij.openapi.util.TextRange
 import org.jetbrains.kotlin.idea.intentions.SelfTargetingRangeIntention
 import org.jetbrains.kotlin.idea.intentions.branchedTransformations.combineWhenConditions
 import org.jetbrains.kotlin.idea.util.CommentSaver
-import org.jetbrains.kotlin.psi.KtIfExpression
-import org.jetbrains.kotlin.psi.KtPsiFactory
-import org.jetbrains.kotlin.psi.KtWhenExpression
-import org.jetbrains.kotlin.psi.buildExpression
+import org.jetbrains.kotlin.psi.*
 
 class WhenToIfIntention : SelfTargetingRangeIntention<KtWhenExpression>(KtWhenExpression::class.java, "Replace 'when' with 'if'"),
     LowPriorityAction {
@@ -24,6 +21,7 @@ class WhenToIfIntention : SelfTargetingRangeIntention<KtWhenExpression>(KtWhenEx
         val lastEntry = entries.last()
         if (entries.any { it != lastEntry && it.isElse }) return null
         if (entries.all { it.isElse }) return null // 'when' with only 'else' branch is not supported
+        if (element.subjectExpression is KtProperty) return null
         return element.whenKeyword.textRange
     }
 

idea/testData/intentions/branched/ifWhen/whenToIf/variableSubject.kt

@@ -0,0 +1,13 @@
+// IS_APPLICABLE: false
+enum class Type {
+    HYDRO,
+    PYRO
+}
+
+fun select(t: Type): Int {
+    return <caret>when (val i = t.ordinal) {
+        0 -> 1
+        1 -> 42
+        else -> i
+    }
+}

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

@@ -2525,6 +2525,11 @@ public class IntentionTestGenerated extends AbstractIntentionTest {
                     runTest("idea/testData/intentions/branched/ifWhen/whenToIf/kt13884.kt");
                 }
 
+                @TestMetadata("variableSubject.kt")
+                public void testVariableSubject() throws Exception {
+                    runTest("idea/testData/intentions/branched/ifWhen/whenToIf/variableSubject.kt");
+                }
+
                 @TestMetadata("whenWithDotQualifiedExpression.kt")
                 public void testWhenWithDotQualifiedExpression() throws Exception {
                     runTest("idea/testData/intentions/branched/ifWhen/whenToIf/whenWithDotQualifiedExpression.kt");