Catch inadvertent uses of OUString(sal_Unicode) ctor

...with numeric values that are not meant to be characters.  Inspired by
<https://gerrit.libreoffice.org/#/c/16339/> "OUString: add constructor from
single Unicode code point" and ecaf1cb3861c1b519a1495487fc796884cf37b92 "seems
to be what was meant."  Found e46e8d19458fd64ff20b1013e5eeabd07e62379c "Shall
this produce a string representation of a number?" and
f2a0e4032734d6be635f14ade3dea499c29ec6c2 "Don't truncate a UTF-32 code point to
a UTF-16 code unit."

(LIBO_INTERNAL_ONLY mostly because it uses a C++11 delegating ctor for
simplicity, but also because it requires mild modifications to client code, see
additional changes in this commit and some other recent commits.)

Change-Id: I8a156f01d1b772c6052d7afaa088ae13ed234e2b

1 files changed, 11 insertions, 0 deletions

diff --git a/include/rtl/ustring.hxx b/include/rtl/ustring.hxx
index 80d67e843677..2c56443e8219 100644
--- a/include/rtl/ustring.hxx
+++ b/include/rtl/ustring.hxx
@@ -172,6 +172,17 @@ public:
         rtl_uString_newFromStr_WithLength( &pData, &value, 1 );
     }
 
+#if defined LIBO_INTERNAL_ONLY && !defined RTL_STRING_UNITTEST_CONCAT
+    /// @cond INTERNAL
+    // Catch inadvertent conversions to the above ctor (but still allow
+    // construction from char literals):
+    OUString(int) = delete;
+    explicit OUString(char c):
+        OUString(sal_Unicode(static_cast<unsigned char>(c)))
+    {}
+    /// @endcond
+#endif
+
     /**
       New string from a Unicode character buffer array.