[IDE] Don’t return any result if the base expression’s type in postfix completion couldn’t be inferred

Author: ahoppen

lib/IDE/PostfixCompletion.cpp

@@ -156,6 +156,10 @@ void PostfixCompletionCallback::sawSolutionImpl(
   auto *ParsedExpr = CompletionExpr->getBase();
   auto *SemanticExpr = ParsedExpr->getSemanticsProvidingExpr();
 
+  if (!S.hasType(ParsedExpr)) {
+    return;
+  }
+
   auto BaseTy = getTypeForCompletion(S, ParsedExpr);
   // If base type couldn't be determined (e.g. because base expression
   // is an invalid reference), let's not attempt to do a lookup since

test/IDE/complete_pattern.swift

@@ -225,3 +225,13 @@ func testCompleteAfterPatternInClosure() {
 
   // AFTER_PATTERN_IN_CLOSURE-NOT: Begin completions
 }
+
+func testIfLetInClosure(foo: Int?) {
+  func takeClosure(_ x: () -> Void) {}
+
+  takeClosure {
+    if let items#^IF_LET_IN_CLOSURE^# = foo {
+    }
+  }
+  // IF_LET_IN_CLOSURE-NOT: Begin completions
+}