1 files changed, 42 insertions, 0 deletions

diff --git a/utf8.c b/utf8.c
index f563d3738..87fa9e89a 100644
--- a/utf8.c
+++ b/utf8.c
@@ -27,6 +27,7 @@
 # include <langinfo.h>
 #endif
 #include <limits.h>
+#include <locale.h>
 #include <stdarg.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -288,3 +289,44 @@ mprintf(const char *fmt, ...)
         va_end(ap);
         return ret;
 }
+
+/*
+ * Set up libc for multibyte output in the user's chosen locale.
+ *
+ * XXX: we are known to have problems with Turkish (i/I confusion) so we
+ *      deliberately fall back to the C locale for now. Longer term we should
+ *      always prefer to select C.[encoding] if possible, but there's no
+ *      standardisation in locales between systems, so we'll need to survey
+ *      what's out there first.
+ */
+void
+msetlocale(void)
+{
+        const char *vars[] = { "LC_ALL", "LC_CTYPE", "LANG", NULL };
+        char *cp;
+        int i;
+
+        /*
+         * We can't yet cope with dotless/dotted I in Turkish locales,
+         * so fall back to the C locale for these.
+         */
+        for (i = 0; vars[i] != NULL; i++) {
+                if ((cp = getenv(vars[i])) == NULL)
+                        continue;
+                if (strncasecmp(cp, "TR", 2) != 0)
+                        break;
+                /*
+                 * If we're in a UTF-8 locale then prefer to use
+                 * the C.UTF-8 locale (or equivalent) if it exists.
+                 */
+                if ((strcasestr(cp, "UTF-8") != NULL ||
+                    strcasestr(cp, "UTF8") != NULL) &&
+                    (setlocale(LC_CTYPE, "C.UTF-8") != NULL ||
+                    setlocale(LC_CTYPE, "POSIX.UTF-8") != NULL))
+                        return;
+                setlocale(LC_CTYPE, "C");
+                return;
+        }
+        /* We can handle this locale */
+        setlocale(LC_CTYPE, "");
+}