5 files changed, 47 insertions, 3 deletions

diff --git a/scp.c b/scp.c
index c67cd71df..b4db85198 100644
--- a/scp.c
+++ b/scp.c
@@ -379,7 +379,7 @@ main(int argc, char **argv)
 	/* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
 	sanitise_stdfd();
 
-	setlocale(LC_CTYPE, "");
+	msetlocale();
 
 	/* Copy argv, because we modify it */
 	newargv = xcalloc(MAXIMUM(argc + 1, 1), sizeof(*newargv));
diff --git a/sftp.c b/sftp.c
index af6e3a69a..2b8fdabfb 100644
--- a/sftp.c
+++ b/sftp.c
@@ -2272,7 +2272,7 @@ main(int argc, char **argv)
 	ssh_malloc_init();	/* must be called before any mallocs */
 	/* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
 	sanitise_stdfd();
-	setlocale(LC_CTYPE, "");
+	msetlocale();
 
 	__progname = ssh_get_progname(argv[0]);
 	memset(&args, '\0', sizeof(args));
diff --git a/ssh.c b/ssh.c
index 8aa8daae4..ee0b16dc2 100644
--- a/ssh.c
+++ b/ssh.c
@@ -109,6 +109,7 @@
 #include "version.h"
 #include "ssherr.h"
 #include "myproposal.h"
+#include "utf8.h"
 
 #ifdef ENABLE_PKCS11
 #include "ssh-pkcs11.h"
@@ -589,7 +590,7 @@ main(int ac, char **av)
 	 */
 	umask(022);
 
-	setlocale(LC_CTYPE, "");
+	msetlocale();
 
 	/*
 	 * Initialize option structure to indicate that no values have been
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, "");
+}
diff --git a/utf8.h b/utf8.h
index 43ce1d55d..88c5a34a3 100644
--- a/utf8.h
+++ b/utf8.h
@@ -22,3 +22,4 @@ int	 fmprintf(FILE *, const char *, ...)
 int	 vfmprintf(FILE *, const char *, va_list);
 int	 snmprintf(char *, size_t, int *, const char *, ...)
 	     __attribute__((format(printf, 4, 5)));
+void	 msetlocale(void);