Merge pull request #12438 from gregomni/4082

[AST] Name lookup shouldn't find pattern declarations later in the same condition.

Author: gregomni

lib/AST/NameLookupImpl.h

@@ -121,10 +121,16 @@ class FindLocalVal : public StmtVisitor<FindLocalVal> {
   }
 
   void checkStmtCondition(const StmtCondition &Cond) {
-    for (auto entry : Cond)
-      if (auto *P = entry.getPatternOrNull())
-        if (!isReferencePointInRange(entry.getSourceRange()))
+    SourceLoc start = SourceLoc();
+    for (auto entry : Cond) {
+      if (start.isInvalid())
+        start = entry.getStartLoc();
+      if (auto *P = entry.getPatternOrNull()) {
+        SourceRange previousConditionsToHere = SourceRange(start, entry.getEndLoc());
+        if (!isReferencePointInRange(previousConditionsToHere))
           checkPattern(P, DeclVisibilityKind::LocalVariable);
+      }
+    }
   }
 
   void visitIfStmt(IfStmt *S) {

test/NameBinding/name_lookup.swift

@@ -566,3 +566,9 @@ func foo1() {
   _ = MyGenericEnum<Int>.One // expected-error {{enum type 'MyGenericEnum<Int>' has no case 'One'; did you mean 'one'}}{{26-29=one}}
   _ = MyGenericEnum<Int>.OneTwo // expected-error {{enum type 'MyGenericEnum<Int>' has no case 'OneTwo'; did you mean 'oneTwo'}}{{26-32=oneTwo}}
 }
+
+// SR-4082
+func foo2() {
+  let x = 5
+  if x < 0, let x = Optional(1) { } // expected-warning {{immutable value 'x' was never used; consider replacing with '_' or removing it}}
+}