Fixed a false positive related to binding patterns and spread expressions

src/compiler/checker.ts

@@ -27970,7 +27970,8 @@ namespace ts {
             // type with those properties for which the binding pattern specifies a default value.
             // If the object literal is spread into another object literal, skip this step and let the top-level object
             // literal handle it instead.
-            if (contextualTypeHasPattern && node.parent.kind !== SyntaxKind.SpreadAssignment) {
+            const spreadOrOutsidePossibleObjectParent = findAncestor(node, n => n.kind === SyntaxKind.SpreadAssignment || isStatement(n) || isArrowFunction(n))!;
+            if (contextualTypeHasPattern && spreadOrOutsidePossibleObjectParent.kind !== SyntaxKind.SpreadAssignment) {
                 for (const prop of getPropertiesOfType(contextualType)) {
                     if (!propertiesTable.get(prop.escapedName) && !getPropertyOfType(spread, prop.escapedName)) {
                         if (!(prop.flags & SymbolFlags.Optional)) {

tests/baselines/reference/spreadExpressionWithinIIFEReturnAssignedtoPattern.symbols

@@ -0,0 +1,11 @@
+=== tests/cases/compiler/spreadExpressionWithinIIFEReturnAssignedtoPattern.ts ===
+// repro #49585
+
+const { value } = (() => ({
+>value : Symbol(value, Decl(spreadExpressionWithinIIFEReturnAssignedtoPattern.ts, 2, 7))
+
+  value: "",
+>value : Symbol(value, Decl(spreadExpressionWithinIIFEReturnAssignedtoPattern.ts, 2, 27))
+
+  ...(true ? {} : {}),
+}))();

tests/baselines/reference/spreadExpressionWithinIIFEReturnAssignedtoPattern.types

@@ -0,0 +1,23 @@
+=== tests/cases/compiler/spreadExpressionWithinIIFEReturnAssignedtoPattern.ts ===
+// repro #49585
+
+const { value } = (() => ({
+>value : string
+>(() => ({  value: "",  ...(true ? {} : {}),}))() : { value: string; }
+>(() => ({  value: "",  ...(true ? {} : {}),})) : () => { value: string; }
+>() => ({  value: "",  ...(true ? {} : {}),}) : () => { value: string; }
+>({  value: "",  ...(true ? {} : {}),}) : { value: string; }
+>{  value: "",  ...(true ? {} : {}),} : { value: string; }
+
+  value: "",
+>value : string
+>"" : ""
+
+  ...(true ? {} : {}),
+>(true ? {} : {}) : {}
+>true ? {} : {} : {}
+>true : true
+>{} : {}
+>{} : {}
+
+}))();

tests/cases/compiler/spreadExpressionWithinIIFEReturnAssignedtoPattern.ts

@@ -0,0 +1,8 @@
+// @noEmit: true
+
+// repro #49585
+
+const { value } = (() => ({
+  value: "",
+  ...(true ? {} : {}),
+}))();