Force Turkish locales back to C/POSIX; bz#2643

Turkish locales are unique in their handling of the letters 'i' and
'I' (yes, they are different letters) and OpenSSH isn't remotely
prepared to deal with that. For now, the best we can do is to force
OpenSSH to use the C/POSIX locale and try to preserve the UTF-8
encoding if possible.

ok dtucker@

1 files changed, 42 insertions, 0 deletions

diff --git a/utf8.c b/utf8.c
index f563d373..87fa9e89 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, "");
+}