Fix bug 19740; round-tripping a pointer through a stream doesn't work

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@209305 91177308-0d34-0410-b5e6-96231b3b80d8
(cherry picked from commit 854ad932c8926b373d1dab71b440ac79e3293c4c)

2 files changed, 21 insertions, 3 deletions

diff --git a/include/locale b/include/locale
index a60e09344..3e87e9f34 100644
--- a/include/locale
+++ b/include/locale
@@ -1180,11 +1180,11 @@ num_get<_CharT, _InputIterator>::do_get(iter_type __b, iter_type __e,
             break;
     }
     // Stage 3
-    __a[sizeof(__a)-1] = 0;
+    __buf.resize(__a_end - __a);
 #ifdef _LIBCPP_LOCALE__L_EXTENSIONS
-    if (sscanf_l(__a, _LIBCPP_GET_C_LOCALE, "%p", &__v) != 1)
+    if (sscanf_l(__buf.c_str(), _LIBCPP_GET_C_LOCALE, "%p", &__v) != 1)
 #else
-    if (__sscanf_l(__a, __cloc(), "%p", &__v) != 1)
+    if (__sscanf_l(__buf.c_str(), __cloc(), "%p", &__v) != 1)
 #endif
         __err = ios_base::failbit;
     // EOF checked
diff --git a/test/input.output/iostream.format/input.streams/istream.formatted/istream.formatted.arithmetic/pointer.pass.cpp b/test/input.output/iostream.format/input.streams/istream.formatted/istream.formatted.arithmetic/pointer.pass.cpp
index 5eda96fe6..52b356664 100644
--- a/test/input.output/iostream.format/input.streams/istream.formatted/istream.formatted.arithmetic/pointer.pass.cpp
+++ b/test/input.output/iostream.format/input.streams/istream.formatted/istream.formatted.arithmetic/pointer.pass.cpp
@@ -76,4 +76,22 @@ int main()
         assert(!is.eof());
         assert(!is.fail());
     }
+    {
+        testbuf<char> sb("12345678");
+        std::istream is(&sb);
+        void* n = 0;
+        is >> n;
+        assert(n == (void*)0x12345678);
+        assert( is.eof());
+        assert(!is.fail());
+    }
+    {
+        testbuf<wchar_t> sb(L"12345678");
+        std::wistream is(&sb);
+        void* n = 0;
+        is >> n;
+        assert(n == (void*)0x12345678);
+        assert( is.eof());
+        assert(!is.fail());
+    }
 }