diff --git a/clang/lib/StaticAnalyzer/Checkers/UndefResultChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/UndefResultChecker.cpp
index 673356319833..3f6549de56b0 100644
--- a/clang/lib/StaticAnalyzer/Checkers/UndefResultChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/UndefResultChecker.cpp
@@ -40,6 +40,15 @@ void UndefResultChecker::checkPostStmt(const BinaryOperator *B,
   ProgramStateRef state = C.getState();
   const LocationContext *LCtx = C.getLocationContext();
   if (state->getSVal(B, LCtx).isUndef()) {
+
+    // Do not report assignments of uninitialized values inside swap functions.
+    // This should allow to swap partially uninitialized structs
+    // (radar://14129997)
+    if (const FunctionDecl *EnclosingFunctionDecl =
+        dyn_cast<FunctionDecl>(C.getStackFrame()->getDecl()))
+      if (C.getCalleeName(EnclosingFunctionDecl) == "swap")
+        return;
+
     // Generate an error node.
     ExplodedNode *N = C.generateSink();
     if (!N)
diff --git a/clang/lib/StaticAnalyzer/Checkers/UndefinedAssignmentChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/UndefinedAssignmentChecker.cpp
index e04f49c3746d..016e3c804592 100644
--- a/clang/lib/StaticAnalyzer/Checkers/UndefinedAssignmentChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/UndefinedAssignmentChecker.cpp
@@ -38,6 +38,14 @@ void UndefinedAssignmentChecker::checkBind(SVal location, SVal val,
   if (!val.isUndef())
     return;
 
+  // Do not report assignments of uninitialized values inside swap functions.
+  // This should allow to swap partially uninitialized structs
+  // (radar://14129997)
+  if (const FunctionDecl *EnclosingFunctionDecl =
+      dyn_cast<FunctionDecl>(C.getStackFrame()->getDecl()))
+    if (C.getCalleeName(EnclosingFunctionDecl) == "swap")
+      return;
+
   ExplodedNode *N = C.generateSink();
 
   if (!N)
diff --git a/clang/test/Analysis/uninit-vals-ps-region.m b/clang/test/Analysis/uninit-vals-ps-region.m
index 614ce2fc3354..a4aa5a114aeb 100644
--- a/clang/test/Analysis/uninit-vals-ps-region.m
+++ b/clang/test/Analysis/uninit-vals-ps-region.m
@@ -76,3 +76,18 @@ void PR10163 (void) {
   test_PR10163(x[1]); // expected-warning{{uninitialized value}}
 }
 
+struct MyStr {
+  int x;
+  int y;
+};
+void swap(struct MyStr *To, struct MyStr *From) {
+  // This is not really a swap but close enough for our test.
+  To->x = From->x;
+  To->y = From->y; // no warning
+}
+int test_undefined_member_assignment_in_swap(struct MyStr *s2) {
+  struct MyStr s1;
+  s1.x = 5;
+  swap(s2, &s1);
+  return s2->y; // expected-warning{{Undefined or garbage value returned to caller}}
+}