Prevent temporary variable from substituting to branches of ternary conditional expression, since it can sometimes violate evaluation order

js/js.inliner/src/org/jetbrains/kotlin/js/inline/clean/TemporaryVariableElimination.kt

@@ -64,6 +64,16 @@ internal class TemporaryVariableElimination(private val root: JsStatement) {
                 return super.visit(x, ctx)
             }
 
+            override fun visit(x: JsIf, ctx: JsContext<*>): Boolean {
+                accept(x.ifExpression)
+                lastAssignedVars.clear()
+
+                accept(x.thenStatement)
+                x.elseStatement?.let { accept(it) }
+
+                return false
+            }
+
             override fun visit(x: JsInvocation, ctx: JsContext<*>): Boolean {
                 x.arguments.asReversed().forEach { accept(it) }
                 accept(x.qualifier)
@@ -129,6 +139,16 @@ internal class TemporaryVariableElimination(private val root: JsStatement) {
                 x.collectFreeVariables().forEach { useVariable(it); useVariable(it) }
                 return super.visit(x, ctx)
             }
+
+            override fun visit(x: JsConditional, ctx: JsContext<*>): Boolean {
+                accept(x.testExpression)
+                lastAssignedVars.clear()
+
+                accept(x.thenExpression)
+                accept(x.elseExpression)
+
+                return false
+            }
         }.accept(root)
     }
 

js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/InlineEvaluationOrderTestGenerated.java

@@ -245,6 +245,12 @@ public class InlineEvaluationOrderTestGenerated extends AbstractInlineEvaluation
         doTest(fileName);
     }
 
+    @TestMetadata("ternaryConditional.kt")
+    public void testTernaryConditional() throws Exception {
+        String fileName = KotlinTestUtils.navigationMetadata("js/js.translator/testData/inlineEvaluationOrder/cases/ternaryConditional.kt");
+        doTest(fileName);
+    }
+
     @TestMetadata("while.kt")
     public void testWhile() throws Exception {
         String fileName = KotlinTestUtils.navigationMetadata("js/js.translator/testData/inlineEvaluationOrder/cases/while.kt");

js/js.translator/testData/inlineEvaluationOrder/cases/ternaryConditional.kt

@@ -0,0 +1,20 @@
+package foo
+
+// CHECK_NOT_CALLED: bar_vux9f0$
+
+inline fun bar(n: Int, x: Int) = if (n <= 5) x else 10
+
+fun test(n: Int): Int = bar(n, fizz(n))
+
+fun box(): String {
+    var result = test(4)
+    if (result != 4) return "fail1: $result"
+
+    result = test(8)
+    if (result != 10) return "fail2: $result"
+
+    var log = pullLog()
+    if (log != "fizz(4);fizz(8);") return "fail_log: $log"
+
+    return "OK"
+}