diff --git a/clang/lib/StaticAnalyzer/Checkers/CStringChecker.cpp b/clang/lib/StaticAnalyzer/Checkers/CStringChecker.cpp
--- a/clang/lib/StaticAnalyzer/Checkers/CStringChecker.cpp
+++ b/clang/lib/StaticAnalyzer/Checkers/CStringChecker.cpp
@@ -848,7 +848,15 @@
     SValBuilder &svalBuilder = C.getSValBuilder();
     QualType sizeTy = svalBuilder.getContext().getSizeType();
     const StringLiteral *strLit = cast<StringRegion>(MR)->getStringLiteral();
-    return svalBuilder.makeIntVal(strLit->getByteLength(), sizeTy);
+    unsigned countx = 0;
+    // get the number of string literal characters by the target's "code unit"
+    // size, checking for an embedded literal of 0 up to the string literal's
+    // length.
+    for (countx = 0;
+         countx < strLit->getLength() && (strLit->getCodeUnit(countx) != 0);
+         countx++)
+      ;
+    return svalBuilder.makeIntVal(countx, sizeTy);
   }
   case MemRegion::SymbolicRegionKind:
   case MemRegion::AllocaRegionKind:
diff --git a/clang/test/Analysis/string.c b/clang/test/Analysis/string.c
--- a/clang/test/Analysis/string.c
+++ b/clang/test/Analysis/string.c
@@ -1652,3 +1652,8 @@
   __builtin___memset_chk(&x, 0, sizeof(x), __builtin_object_size(&x, 0));
   clang_analyzer_eval(x == 0); // expected-warning{{TRUE}}
 }
+
+void strcpy_no_overflow_2(char *y) {
+  char x[3];
+  strcpy(x, "12\0");
+}