Use nl_langinfo_l with an explicitly created locale

(where empty string arg to newlocale, per SUSv4, means "an implementation-
defined native environment.  This correspons to the value of the associated
environment variables, LC_* and LANG") instead of relying on whatever setlocale
would be in effect here.

Also, nl_langinfo_l is less of an MT nightmare than nl_langinfo, which is of
benefit once the last remaining use of nl_langinfo in sal/osl/unx/nlsupport.cxx
will also have been changed to nl_langinfo_l.

loplugin:nullptr needs a little hack, as SUSv4 locale_t could be anything from
an integer type to a pointer type.

Change-Id: Ic35dcbc2e0a4f650694b48df12470dd89476dff5

compilerplugins/clang/nullptr.cxx

@@ -12,6 +12,7 @@
 #include <limits>
 #include <set>
 
+#include "check.hxx"
 #include "plugin.hxx"
 
 namespace {
@@ -128,6 +129,11 @@ bool Nullptr::VisitImplicitCastExpr(CastExpr const * expr) {
     case Expr::NPCK_CXX11_nullptr:
         break;
     default:
+        if (loplugin::TypeCheck(expr->getType()).Typedef("locale_t")
+            .GlobalNamespace())
+        {
+            break; // POSIX locale_t is left unspecified
+        }
         handleNull(expr->getSubExpr(), expr->getCastKindName(), k);
         break;
     }

i18nutil/source/utility/paper.cxx

@@ -290,39 +290,43 @@ PaperInfo PaperInfo::getSystemDefaultPaper()
         }
 
 #if defined(LC_PAPER) && defined(_GNU_SOURCE)
-
-        union paperword { char *string; int word; };
-
         // try LC_PAPER
-        paperword w, h;
-        w.string = nl_langinfo(_NL_PAPER_WIDTH);
-        h.string = nl_langinfo(_NL_PAPER_HEIGHT);
-
-        //glibc stores sizes as integer mm units
-        w.word *= 100;
-        h.word *= 100;
-
-        for ( size_t i = 0; i < nTabSize; ++i )
+        locale_t loc = newlocale(LC_PAPER_MASK, "", static_cast<locale_t>(0));
+        if (loc != static_cast<locale_t>(0))
         {
-            if (i == PAPER_USER) continue;
+            union paperword { char *string; int word; };
+            paperword w, h;
+            w.string = nl_langinfo_l(_NL_PAPER_WIDTH, loc);
+            h.string = nl_langinfo_l(_NL_PAPER_HEIGHT, loc);
+
+            freelocale(loc);
 
-            //glibc stores sizes as integer mm units, and so is inaccurate. To
-            //find a standard paper size we calculate the standard paper sizes
-            //into equally inaccurate mm and compare
-            long width = (aDinTab[i].m_nWidth + 50) / 100;
-            long height = (aDinTab[i].m_nHeight + 50) / 100;
+            //glibc stores sizes as integer mm units
+            w.word *= 100;
+            h.word *= 100;
 
-            if (width == w.word/100 && height == h.word/100)
+            for ( size_t i = 0; i < nTabSize; ++i )
             {
-                w.word = aDinTab[i].m_nWidth;
-                h.word = aDinTab[i].m_nHeight;
-                break;
+                if (i == PAPER_USER) continue;
+
+                //glibc stores sizes as integer mm units, and so is inaccurate.
+                //To find a standard paper size we calculate the standard paper
+                //sizes into equally inaccurate mm and compare
+                long width = (aDinTab[i].m_nWidth + 50) / 100;
+                long height = (aDinTab[i].m_nHeight + 50) / 100;
+
+                if (width == w.word/100 && height == h.word/100)
+                {
+                    w.word = aDinTab[i].m_nWidth;
+                    h.word = aDinTab[i].m_nHeight;
+                    break;
+                }
             }
-        }
 
-        aInstance = PaperInfo(w.word, h.word);
-        bInitialized = true;
-        return aInstance;
+            aInstance = PaperInfo(w.word, h.word);
+            bInitialized = true;
+            return aInstance;
+        }
 #endif
     }
 #endif