Avoid empty strings for yaz_iconv_open

yaz_iconv_open apparently returns a non-null handle in case of
to=(null) and from="" .. Avoid we call it this way. This resulted
in bad records for Pazpar2 and was introduced in YAZ 4.1.5.

diff --git a/src/record_render.c b/src/record_render.c
index 16351a2..ddfd391 100644 (file)
--- a/src/record_render.c
+++ b/src/record_render.c
@@ -28,7 +28,7 @@ static yaz_iconv_t iconv_create_charset(const char *record_charset,
     char *from_set1 = 0;
     char *from_set2 = 0;
     char *to_set = 0;
     char *from_set1 = 0;
     char *from_set2 = 0;
     char *to_set = 0;

-    if (record_charset)
+    if (record_charset && *record_charset)

     {
         char *cp = charset_buf;
         
     {
         char *cp = charset_buf;