Use utf-8 variant of strftime to format log file paths.

strftime assumes the format string is in locale encoding, which mangles log file paths that are in utf-8.

Fixes #767
Fixes #945

src/common/text.c

@@ -540,7 +540,6 @@ log_create_pathname (char *servname, char *channame, char *netname)
 {
 	char fname[384];
 	char fnametime[384];
-	struct tm *tm;
 	time_t now;
 
 	if (!netname)
@@ -568,8 +567,7 @@ log_create_pathname (char *servname, char *channame, char *netname)
 
 	/* insert time/date */
 	now = time (NULL);
-	tm = localtime (&now);
-	strftime_validated (fnametime, sizeof (fnametime), fname, tm);
+	strftime_utf8 (fnametime, sizeof (fnametime), fname, now);
 
 	/* create final path/filename */
 	if (logmask_is_fullpath ())

src/common/util.c

@@ -2211,6 +2211,8 @@ challengeauth_response (char *username, char *password, char *challenge)
  * it returns 0 if the escaped format string is too large.
  *
  * Based upon work from znc-msvc project.
+ *
+ * This assumes format is a locale-encoded string. For utf-8 strings, use strftime_utf8
  */
 size_t
 strftime_validated (char *dest, size_t destsize, const char *format, const struct tm *time)
@@ -2278,3 +2280,17 @@ strftime_validated (char *dest, size_t destsize, const char *format, const struc
 	return strftime (dest, destsize, safe_format, time);
 #endif
 }
+
+/**
+ * \brief Similar to strftime except it works with utf-8 formats, since strftime treats the format as locale-encoded.
+ */
+gsize
+strftime_utf8 (char *dest, gsize destsize, const char *format, time_t time)
+{
+	gsize result;
+	GDate* date = g_date_new ();
+	g_date_set_time_t (date, time);
+	result = g_date_strftime (dest, destsize, format, date);
+	g_date_free (date);
+	return result;
+}

src/common/util.h

@@ -82,4 +82,5 @@ char *encode_sasl_pass_blowfish (char *user, char *pass, char *data);
 char *encode_sasl_pass_aes (char *user, char *pass, char *data);
 char *challengeauth_response (char *username, char *password, char *challenge);
 size_t strftime_validated (char *dest, size_t destsize, const char *format, const struct tm *time);
+size_t strftime_utf8 (char *dest, size_t destsize, const char *format, time_t time);
 #endif