bug#3964 and related issues: FTB problems with charsets where one byte can match many

correct prefix compare with my_strnncoll


include/m_ctype.h:
  6th argument to my_strncoll to handle prefix comparison
myisam/ft_boolean_search.c:
  bug#3964 and related issues: problems with charsets where one byte can match many
  *correct* prefix compare with my_strnncoll
  *correct* backup of info->lastkey
mysql-test/r/fulltext.result:
  6th argument to my_strncoll to handle prefix comparison
mysql-test/t/fulltext.test:
  6th argument to my_strncoll to handle prefix comparison
mysys/my_handler.c:
  6th argument to my_strncoll to handle prefix comparison
sql/sql_parse.cc:
  cleanup
strings/ctype-big5.c:
  6th argument to my_strncoll to handle prefix comparison
strings/ctype-bin.c:
  6th argument to my_strncoll to handle prefix comparison
strings/ctype-czech.c:
  6th argument to my_strncoll to handle prefix comparison
strings/ctype-gbk.c:
  6th argument to my_strncoll to handle prefix comparison
strings/ctype-latin1.c:
  6th argument to my_strncoll to handle prefix comparison
strings/ctype-mb.c:
  6th argument to my_strncoll to handle prefix comparison
strings/ctype-simple.c:
  6th argument to my_strncoll to handle prefix comparison
strings/ctype-sjis.c:
  6th argument to my_strncoll to handle prefix comparison
strings/ctype-tis620.c:
  6th argument to my_strncoll to handle prefix comparison
strings/ctype-uca.c:
  6th argument to my_strncoll to handle prefix comparison
strings/ctype-ucs2.c:
  6th argument to my_strncoll to handle prefix comparison
strings/ctype-utf8.c:
  6th argument to my_strncoll to handle prefix comparison
strings/ctype-win1250ch.c:
  6th argument to my_strncoll to handle prefix comparison

19 files changed, 143 insertions, 60 deletions

diff --git a/include/m_ctype.h b/include/m_ctype.h
index 9502805b017..475f73f16c2 100644
--- a/include/m_ctype.h
+++ b/include/m_ctype.h
@@ -104,7 +104,7 @@ typedef struct my_collation_handler_st
 {
   /* Collation routines */
   int     (*strnncoll)(struct charset_info_st *,
-		       const uchar *, uint, const uchar *, uint);
+		       const uchar *, uint, const uchar *, uint, my_bool);
   int     (*strnncollsp)(struct charset_info_st *,
 		       const uchar *, uint, const uchar *, uint);
   int     (*strnxfrm)(struct charset_info_st *,
@@ -251,7 +251,7 @@ extern CHARSET_INFO my_charset_cp1250_czech_ci;
 extern int  my_strnxfrm_simple(CHARSET_INFO *, uchar *, uint, const uchar *,
 			       uint); 
 extern int  my_strnncoll_simple(CHARSET_INFO *, const uchar *, uint,
-				const uchar *, uint);
+				const uchar *, uint, my_bool);
 
 extern int  my_strnncollsp_simple(CHARSET_INFO *, const uchar *, uint,
 				const uchar *, uint);
@@ -385,7 +385,7 @@ extern my_bool my_parse_charset_xml(const char *bug, uint len,
 #define my_binary_compare(s)	      ((s)->state  & MY_CS_BINSORT)
 #define use_strnxfrm(s)               ((s)->state  & MY_CS_STRNXFRM)
 #define my_strnxfrm(s, a, b, c, d)    ((s)->coll->strnxfrm((s), (a), (b), (c), (d)))
-#define my_strnncoll(s, a, b, c, d)   ((s)->coll->strnncoll((s), (a), (b), (c), (d)))
+#define my_strnncoll(s, a, b, c, d) ((s)->coll->strnncoll((s), (a), (b), (c), (d), 0))
 #define my_like_range(s, a, b, c, d, e, f, g, h, i, j) \
    ((s)->coll->like_range((s), (a), (b), (c), (d), (e), (f), (g), (h), (i), (j)))
 #define my_wildcmp(cs,s,se,w,we,e,o,m)	((cs)->coll->wildcmp((cs),(s),(se),(w),(we),(e),(o),(m)))
diff --git a/myisam/ft_boolean_search.c b/myisam/ft_boolean_search.c
index 345cd3ceb0c..cac4d08f5d6 100644
--- a/myisam/ft_boolean_search.c
+++ b/myisam/ft_boolean_search.c
@@ -53,10 +53,10 @@ static double _nwghts[11]=
  -3.796875000000000};
 static double *nwghts=_nwghts+5; /* nwghts[i] = -0.5*1.5**i */
 
-#define FTB_FLAG_TRUNC 1                  /* MUST be 1                  */
+#define FTB_FLAG_TRUNC 1                  /*                            */
 #define FTB_FLAG_YES   2                  /*  no two from these three   */
 #define FTB_FLAG_NO    4                  /*   YES, NO, WONLY           */
-#define FTB_FLAG_WONLY 8                  /*  should be ever set both   */
+#define FTB_FLAG_WONLY 8                  /*  should be _ever_ set both */
 
 typedef struct st_ftb_expr FTB_EXPR;
 struct st_ftb_expr
@@ -157,6 +157,7 @@ static void _ftb_parse_query(FTB *ftb, byte **start, byte *end,
                                      w.len+extra));
         ftbw->len=w.len+1;
         ftbw->flags=0;
+        ftbw->off=0;
         if (param.yesno>0) ftbw->flags|=FTB_FLAG_YES;
         if (param.yesno<0) ftbw->flags|=FTB_FLAG_NO;
         if (param.trunc)   ftbw->flags|=FTB_FLAG_TRUNC;
@@ -203,23 +204,26 @@ static int _ftb_no_dupes_cmp(void* not_used __attribute__((unused)),
 static int _ft2_search(FTB *ftb, FTB_WORD *ftbw, my_bool init_search)
 {
   int r;
-  uint off;
   int subkeys=1;
   my_bool can_go_down;
   MI_INFO *info=ftb->info;
+  uint off, extra=HA_FT_WLEN+info->s->base.rec_reflength;
+  byte *lastkey_buf=ftbw->word+ftbw->off;
+
+  if (ftbw->flags & FTB_FLAG_TRUNC)
+    lastkey_buf+=ftbw->len;
 
   if (init_search)
   {
     ftbw->key_root=info->s->state.key_root[ftb->keynr];
     ftbw->keyinfo=info->s->keyinfo+ftb->keynr;
-    ftbw->off=0;
 
     r=_mi_search(info, ftbw->keyinfo, (uchar*) ftbw->word, ftbw->len,
                  SEARCH_FIND | SEARCH_BIGGER, ftbw->key_root);
   }
   else
   {
-    r=_mi_search(info, ftbw->keyinfo, (uchar*) ftbw->word+ftbw->off,
+    r=_mi_search(info, ftbw->keyinfo, (uchar*) lastkey_buf,
                    USE_WHOLE_KEY, SEARCH_BIGGER, ftbw->key_root);
   }
 
@@ -230,7 +234,7 @@ static int _ft2_search(FTB *ftb, FTB_WORD *ftbw, my_bool init_search)
     if (can_go_down)
     {
       /* going down ? */
-      off=info->lastkey_length-HA_FT_WLEN-info->s->base.rec_reflength;
+      off=info->lastkey_length-extra;
       subkeys=ft_sintXkorr(info->lastkey+off);
     }
     if (subkeys<0 || info->lastpos < info->state->data_file_length)
@@ -243,11 +247,11 @@ static int _ft2_search(FTB *ftb, FTB_WORD *ftbw, my_bool init_search)
   if (!r && !ftbw->off)
   {
     r= mi_compare_text(ftb->charset,
-                       info->lastkey + (ftbw->flags & FTB_FLAG_TRUNC),
-                       ftbw->len     - (ftbw->flags & FTB_FLAG_TRUNC),
-              (uchar*) ftbw->word    + (ftbw->flags & FTB_FLAG_TRUNC),
-                       ftbw->len     - (ftbw->flags & FTB_FLAG_TRUNC),
-                       0,0);
+                       info->lastkey+1,
+                       info->lastkey_length-extra-1,
+              (uchar*) ftbw->word+1,
+                       ftbw->len-1,
+             (my_bool) (ftbw->flags & FTB_FLAG_TRUNC),0);
   }
 
   if (r) /* not found */
@@ -269,8 +273,7 @@ static int _ft2_search(FTB *ftb, FTB_WORD *ftbw, my_bool init_search)
     }
 
     /* going up to the first-level tree to continue search there */
-    _mi_dpointer(info, (uchar*) (ftbw->word+ftbw->off+HA_FT_WLEN),
-                 ftbw->key_root);
+    _mi_dpointer(info, (uchar*) (lastkey_buf+HA_FT_WLEN), ftbw->key_root);
     ftbw->key_root=info->s->state.key_root[ftb->keynr];
     ftbw->keyinfo=info->s->keyinfo+ftb->keynr;
     ftbw->off=0;
@@ -278,7 +281,10 @@ static int _ft2_search(FTB *ftb, FTB_WORD *ftbw, my_bool init_search)
   }
 
   /* matching key found */
-  memcpy(ftbw->word+ftbw->off, info->lastkey, info->lastkey_length);
+  memcpy(lastkey_buf, info->lastkey, info->lastkey_length);
+  if (lastkey_buf == ftbw->word)
+    ftbw->len=info->lastkey_length-extra;
+
   /* going down ? */
   if (subkeys<0)
   {
@@ -291,7 +297,7 @@ static int _ft2_search(FTB *ftb, FTB_WORD *ftbw, my_bool init_search)
     ftbw->keyinfo=& info->s->ft2_keyinfo;
     r=_mi_search_first(info, ftbw->keyinfo, ftbw->key_root);
     DBUG_ASSERT(r==0);  /* found something */
-    memcpy(ftbw->word+off, info->lastkey, info->lastkey_length);
+    memcpy(lastkey_buf+off, info->lastkey, info->lastkey_length);
   }
   ftbw->docid[0]=info->lastpos;
   return 0;
@@ -356,7 +362,7 @@ static void _ftb_init_index_search(FT_INFO *ftb)
       else
         reset_tree(& ftb->no_dupes);
     }
-
+     
     if (_ft2_search(ftb, ftbw, 1))
       return;
   }
diff --git a/mysql-test/r/fulltext.result b/mysql-test/r/fulltext.result
index 3106602e718..d13c9a9c51c 100644
--- a/mysql-test/r/fulltext.result
+++ b/mysql-test/r/fulltext.result
@@ -363,3 +363,14 @@ SELECT t, collation(t) FROM t1 WHERE MATCH t AGAINST ('Osnabrueck');
 t	collation(t)
 aus Osnabrück	latin1_german2_ci
 DROP TABLE t1;
+CREATE TABLE t1 (s varchar(255), FULLTEXT (s)) DEFAULT CHARSET=utf8;
+insert into t1 (s) values ('pära para para'),('para para para');
+select * from t1 where match(s) against('para' in boolean mode);
+s
+pära para para
+para para para
+select * from t1 where match(s) against('par*' in boolean mode);
+s
+pära para para
+para para para
+DROP TABLE t1;
diff --git a/mysql-test/t/fulltext.test b/mysql-test/t/fulltext.test
index 91e81c5dbe0..66df5b1cb92 100644
--- a/mysql-test/t/fulltext.test
+++ b/mysql-test/t/fulltext.test
@@ -279,3 +279,12 @@ SELECT t, collation(t) FROM t1 WHERE MATCH t AGAINST ('Osnabrück');
 SELECT t, collation(t) FROM t1 WHERE MATCH t AGAINST ('Osnabrueck');
 DROP TABLE t1;
 
+#
+# bug#3964
+#
+
+CREATE TABLE t1 (s varchar(255), FULLTEXT (s)) DEFAULT CHARSET=utf8;
+insert into t1 (s) values ('pära para para'),('para para para');
+select * from t1 where match(s) against('para' in boolean mode);
+select * from t1 where match(s) against('par*' in boolean mode);
+DROP TABLE t1;
diff --git a/mysys/my_handler.c b/mysys/my_handler.c
index de0fba56d21..6003808df25 100644
--- a/mysys/my_handler.c
+++ b/mysys/my_handler.c
@@ -21,13 +21,11 @@ int mi_compare_text(CHARSET_INFO *charset_info, uchar *a, uint a_length,
 		    uchar *b, uint b_length, my_bool part_key,
 		    my_bool skip_end_space)
 {
-  if (part_key && b_length < a_length)
-    a_length=b_length;
   if (skip_end_space)
     return charset_info->coll->strnncollsp(charset_info, a, a_length,
 					   b, b_length);
   return charset_info->coll->strnncoll(charset_info, a, a_length,
-				       b, b_length);
+				       b, b_length, part_key);
 }
 
 
diff --git a/sql/sql_parse.cc b/sql/sql_parse.cc
index e83260b5de0..bafd7dd4b2e 100644
--- a/sql/sql_parse.cc
+++ b/sql/sql_parse.cc
@@ -1191,7 +1191,7 @@ int mysql_table_dump(THD* thd, char* db, char* tbl_name, int fd)
   }
   net_flush(&thd->net);
   if ((error= table->file->dump(thd,fd)))
-    my_error(ER_GET_ERRNO, MYF(0));
+    my_error(ER_GET_ERRNO, MYF(0), error);
 
 err:
   close_thread_tables(thd);
diff --git a/strings/ctype-big5.c b/strings/ctype-big5.c
index f024fa0cc14..af8f5d49654 100644
--- a/strings/ctype-big5.c
+++ b/strings/ctype-big5.c
@@ -251,11 +251,12 @@ static int my_strnncoll_big5_internal(const uchar **a_res,
 
 static int my_strnncoll_big5(CHARSET_INFO *cs __attribute__((unused)), 
 			     const uchar *a, uint a_length,
-			     const uchar *b, uint b_length)
+                             const uchar *b, uint b_length,
+                             my_bool b_is_prefix)
 {
   uint length= min(a_length, b_length);
   int res= my_strnncoll_big5_internal(&a, &b, length);
-  return res ? res : (int) (a_length - b_length);
+  return res ? res : (int)((b_is_prefix ? length : a_length) - b_length);
 }
 
 
diff --git a/strings/ctype-bin.c b/strings/ctype-bin.c
index 7cac8c7c337..35630eb854f 100644
--- a/strings/ctype-bin.c
+++ b/strings/ctype-bin.c
@@ -91,10 +91,20 @@ static uchar bin_char_array[] =
 
 static int my_strnncoll_binary(CHARSET_INFO * cs __attribute__((unused)),
 				const uchar *s, uint slen,
-				const uchar *t, uint tlen)
+				const uchar *t, uint tlen,
+                                my_bool t_is_prefix)
 {
-  int cmp= memcmp(s,t,min(slen,tlen));
-  return cmp ? cmp : (int) (slen - tlen);
+  uint len=min(slen,tlen);
+  int cmp= memcmp(s,t,len);
+  return cmp ? cmp : (int)((t_is_prefix ? len : slen) - tlen);
+}
+
+
+static int my_strnncollsp_binary(CHARSET_INFO * cs __attribute__((unused)),
+                                const uchar *s, uint slen,
+                                const uchar *t, uint tlen)
+{
+  return my_strnncoll_binary(cs,s,slen,t,tlen,0);
 }
 
 
@@ -334,7 +344,7 @@ skip:
 MY_COLLATION_HANDLER my_collation_8bit_bin_handler =
 {
     my_strnncoll_binary,
-    my_strnncoll_binary,
+    my_strnncollsp_binary,
     my_strnxfrm_bin,
     my_like_range_simple,
     my_wildcmp_bin,
diff --git a/strings/ctype-czech.c b/strings/ctype-czech.c
index 2eb2fac46e9..9175451ceb7 100644
--- a/strings/ctype-czech.c
+++ b/strings/ctype-czech.c
@@ -242,12 +242,16 @@ while (1)						\
 
 static int my_strnncoll_czech(CHARSET_INFO *cs __attribute__((unused)),
 			      const uchar * s1, uint len1, 
-			      const uchar * s2, uint len2)
+			      const uchar * s2, uint len2,
+                              my_bool s2_is_prefix)
 {
   int v1, v2;
   const uchar * p1, * p2, * store1, * store2;
   int pass1 = 0, pass2 = 0;
 
+  if (s2_is_prefix && len1 > len2)
+    len1=len2;
+
   p1 = s1;	p2 = s2;
   store1 = s1;	store2 = s2;
 
@@ -276,7 +280,7 @@ int my_strnncollsp_czech(CHARSET_INFO * cs,
 {
   for ( ; slen && s[slen-1] == ' ' ; slen--);
   for ( ; tlen && t[tlen-1] == ' ' ; tlen--);
-  return my_strnncoll_czech(cs,s,slen,t,tlen);
+  return my_strnncoll_czech(cs,s,slen,t,tlen,0);
 }
 
 
diff --git a/strings/ctype-gbk.c b/strings/ctype-gbk.c
index 0dc00a73fa3..18024db3f35 100644
--- a/strings/ctype-gbk.c
+++ b/strings/ctype-gbk.c
@@ -2614,11 +2614,12 @@ int my_strnncoll_gbk_internal(const uchar **a_res, const uchar **b_res,
 
 int my_strnncoll_gbk(CHARSET_INFO *cs __attribute__((unused)),
 		     const uchar *a, uint a_length,
-		     const uchar *b, uint b_length)
+                     const uchar *b, uint b_length,
+                     my_bool b_is_prefix)
 {
   uint length= min(a_length, b_length);
   int res= my_strnncoll_gbk_internal(&a, &b, length);
-  return res ? res : (int) (a_length - b_length);
+  return res ? res : (int) ((b_is_prefix ? length : a_length) - b_length);
 }
 
 
diff --git a/strings/ctype-latin1.c b/strings/ctype-latin1.c
index 0b439964c7c..257d8e37eee 100644
--- a/strings/ctype-latin1.c
+++ b/strings/ctype-latin1.c
@@ -525,7 +525,8 @@ uchar combo2map[]={
 
 static int my_strnncoll_latin1_de(CHARSET_INFO *cs __attribute__((unused)),
 				  const uchar *a, uint a_length,
-				  const uchar *b, uint b_length)
+				  const uchar *b, uint b_length,
+                                  my_bool b_is_prefix)
 {
   const uchar *a_end= a + a_length;
   const uchar *b_end= b + b_length;
@@ -558,7 +559,7 @@ static int my_strnncoll_latin1_de(CHARSET_INFO *cs __attribute__((unused)),
     A simple test of string lengths won't work -- we test to see
     which string ran out first
   */
-  return ((a < a_end || a_extend) ? 1 :
+  return ((a < a_end || a_extend) ? (b_is_prefix ? 0 : 1) :
 	  (b < b_end || b_extend) ? -1 : 0);
 }
 
diff --git a/strings/ctype-mb.c b/strings/ctype-mb.c
index 9b02cd3b3da..129e2f2d9a9 100644
--- a/strings/ctype-mb.c
+++ b/strings/ctype-mb.c
@@ -322,7 +322,7 @@ uint my_instr_mb(CHARSET_INFO *cs,
       int mblen;
       
       if (!cs->coll->strnncoll(cs, (unsigned char*) b,   s_length, 
-      				   (unsigned char*) s, s_length))
+      				   (unsigned char*) s, s_length, 0))
       {
         if (nmatch)
         {
@@ -352,10 +352,19 @@ uint my_instr_mb(CHARSET_INFO *cs,
 
 static int my_strnncoll_mb_bin(CHARSET_INFO * cs __attribute__((unused)),
 				const uchar *s, uint slen,
-				const uchar *t, uint tlen)
+				const uchar *t, uint tlen,
+                                my_bool t_is_prefix)
 {
-  int cmp= memcmp(s,t,min(slen,tlen));
-  return cmp ? cmp : (int) (slen - tlen);
+  uint len=min(slen,tlen);
+  int cmp= memcmp(s,t,len);
+  return cmp ? cmp : (int) ((t_is_prefix ? len : slen) - tlen);
+}
+
+static int my_strnncollsp_mb_bin(CHARSET_INFO * cs __attribute__((unused)),
+                                 const uchar *s, uint slen,
+                                 const uchar *t, uint tlen)
+{
+  return my_strnncoll_mb_bin(cs,s,slen,t,tlen,0);
 }
 
 
@@ -513,7 +522,7 @@ static int my_wildcmp_mb_bin(CHARSET_INFO *cs,
 MY_COLLATION_HANDLER my_collation_mb_bin_handler =
 {
     my_strnncoll_mb_bin,
-    my_strnncoll_mb_bin,
+    my_strnncollsp_mb_bin,
     my_strnxfrm_mb_bin,
     my_like_range_simple,
     my_wildcmp_mb_bin,
diff --git a/strings/ctype-simple.c b/strings/ctype-simple.c
index ba1fc1c424a..3ef8a9d5997 100644
--- a/strings/ctype-simple.c
+++ b/strings/ctype-simple.c
@@ -47,16 +47,19 @@ int my_strnxfrm_simple(CHARSET_INFO * cs,
 }
 
 int my_strnncoll_simple(CHARSET_INFO * cs, const uchar *s, uint slen, 
-			const uchar *t, uint tlen)
+                        const uchar *t, uint tlen,
+                        my_bool t_is_prefix)
 {
   int len = ( slen > tlen ) ? tlen : slen;
   uchar *map= cs->sort_order;
+  if (t_is_prefix && slen > tlen)
+    slen=tlen;
   while (len--)
   {
     if (map[*s++] != map[*t++])
       return ((int) map[s[-1]] - (int) map[t[-1]]);
   }
-  return (int) (slen-tlen);
+  return (int) (slen - tlen);
 }
 
 
diff --git a/strings/ctype-sjis.c b/strings/ctype-sjis.c
index 72666175a1f..cfe59bb2852 100644
--- a/strings/ctype-sjis.c
+++ b/strings/ctype-sjis.c
@@ -232,9 +232,12 @@ static int my_strnncoll_sjis_internal(CHARSET_INFO *cs,
 
 static int my_strnncoll_sjis(CHARSET_INFO *cs __attribute__((unused)),
 			      const uchar *a, uint a_length, 
-			      const uchar *b, uint b_length)
+			      const uchar *b, uint b_length,
+                              my_bool b_is_prefix)
 {
   int res= my_strnncoll_sjis_internal(cs, &a, a_length, &b, b_length);
+  if (b_is_prefix && a_length > b_length)
+    a_length= b_length;
   return res ? res : (int) (a_length - b_length);
 }
 
diff --git a/strings/ctype-tis620.c b/strings/ctype-tis620.c
index e2a138300c3..b9ee8825eef 100644
--- a/strings/ctype-tis620.c
+++ b/strings/ctype-tis620.c
@@ -529,12 +529,16 @@ static uint thai2sortable(uchar *tstr, uint len)
 static
 int my_strnncoll_tis620(CHARSET_INFO *cs __attribute__((unused)),
                         const uchar * s1, uint len1, 
-                        const uchar * s2, uint len2)
+                        const uchar * s2, uint len2,
+                        my_bool s2_is_prefix)
 {
   uchar	buf[80] ;
   uchar *tc1, *tc2;
   int i;
 
+  if (s2_is_prefix && len1 > len2)
+    len1= len2;
+
   tc1= buf;
   if ((len1 + len2 +2) > (int) sizeof(buf))
     tc1= (uchar*) malloc(len1+len2);
diff --git a/strings/ctype-uca.c b/strings/ctype-uca.c
index 81073d47554..ba7d308ec5c 100644
--- a/strings/ctype-uca.c
+++ b/strings/ctype-uca.c
@@ -6704,7 +6704,8 @@ implicit:
 
 static int my_strnncoll_uca(CHARSET_INFO *cs, 
 			    const uchar *s, uint slen,
-			    const uchar *t, uint tlen)
+                            const uchar *t, uint tlen,
+                            my_bool t_is_prefix)
 {
   my_uca_scanner sscanner;
   my_uca_scanner tscanner;
@@ -6720,7 +6721,7 @@ static int my_strnncoll_uca(CHARSET_INFO *cs,
     t_res= my_uca_scanner_next(&tscanner);
   } while ( s_res == t_res && s_res >0);
   
-  return ( s_res - t_res );
+  return  (t_is_prefix && t_res < 0) ? 0 : (s_res - t_res);
 }
 
 
diff --git a/strings/ctype-ucs2.c b/strings/ctype-ucs2.c
index 67340fdd4f4..040fc5f65fd 100644
--- a/strings/ctype-ucs2.c
+++ b/strings/ctype-ucs2.c
@@ -182,7 +182,8 @@ static void my_casedn_str_ucs2(CHARSET_INFO *cs __attribute__((unused)),
 
 static int my_strnncoll_ucs2(CHARSET_INFO *cs, 
 			     const uchar *s, uint slen, 
-			     const uchar *t, uint tlen)
+                             const uchar *t, uint tlen,
+                             my_bool t_is_prefix)
 {
   int s_res,t_res;
   my_wc_t s_wc,t_wc;
@@ -213,7 +214,14 @@ static int my_strnncoll_ucs2(CHARSET_INFO *cs,
     s+=s_res;
     t+=t_res;
   }
-  return ( (se-s) - (te-t) );
+  return t_is_prefix ? t-te : ((se-s) - (te-t));
+}
+
+static int my_strnncollsp_ucs2(CHARSET_INFO *cs, 
+                               const uchar *s, uint slen, 
+                               const uchar *t, uint tlen)
+{
+  return my_strnncoll_ucs2(cs,s,slen,t,tlen,0);
 }
 
 
@@ -1224,8 +1232,9 @@ int my_wildcmp_ucs2_bin(CHARSET_INFO *cs,
 
 static
 int my_strnncoll_ucs2_bin(CHARSET_INFO *cs, 
-				 const uchar *s, uint slen,
-				 const uchar *t, uint tlen)
+                          const uchar *s, uint slen,
+                          const uchar *t, uint tlen,
+                          my_bool t_is_prefix)
 {
   int s_res,t_res;
   my_wc_t s_wc,t_wc;
@@ -1250,7 +1259,14 @@ int my_strnncoll_ucs2_bin(CHARSET_INFO *cs,
     s+=s_res;
     t+=t_res;
   }
-  return ( (se-s) - (te-t) );
+  return t_is_prefix ? t-te : ((se-s) - (te-t));
+}
+
+static int my_strnncollsp_ucs2_bin(CHARSET_INFO *cs, 
+                                   const uchar *s, uint slen, 
+                                   const uchar *t, uint tlen)
+{
+  return my_strnncoll_ucs2_bin(cs,s,slen,t,tlen,0);
 }
 
 
@@ -1374,7 +1390,7 @@ my_bool my_like_range_ucs2(CHARSET_INFO *cs,
 static MY_COLLATION_HANDLER my_collation_ucs2_general_ci_handler =
 {
     my_strnncoll_ucs2,
-    my_strnncoll_ucs2,
+    my_strnncollsp_ucs2,
     my_strnxfrm_ucs2,
     my_like_range_ucs2,
     my_wildcmp_ucs2_ci,
@@ -1387,7 +1403,7 @@ static MY_COLLATION_HANDLER my_collation_ucs2_general_ci_handler =
 static MY_COLLATION_HANDLER my_collation_ucs2_bin_handler =
 {
     my_strnncoll_ucs2_bin,
-    my_strnncoll_ucs2_bin,
+    my_strnncollsp_ucs2_bin,
     my_strnxfrm_ucs2_bin,
     my_like_range_simple,
     my_wildcmp_ucs2_bin,
diff --git a/strings/ctype-utf8.c b/strings/ctype-utf8.c
index 29d2c5d1358..48882f356fd 100644
--- a/strings/ctype-utf8.c
+++ b/strings/ctype-utf8.c
@@ -1802,7 +1802,8 @@ static void my_casedn_str_utf8(CHARSET_INFO *cs, char * s)
 
 static int my_strnncoll_utf8(CHARSET_INFO *cs, 
 			     const uchar *s, uint slen,
-			     const uchar *t, uint tlen)
+                             const uchar *t, uint tlen,
+                             my_bool t_is_prefix)
 {
   int s_res,t_res;
   my_wc_t s_wc,t_wc;
@@ -1833,7 +1834,7 @@ static int my_strnncoll_utf8(CHARSET_INFO *cs,
     s+=s_res;
     t+=t_res;
   }
-  return ( (se-s) - (te-t) );
+  return t_is_prefix ? t-te : ((se-s) - (te-t));
 }
 
 
diff --git a/strings/ctype-win1250ch.c b/strings/ctype-win1250ch.c
index 2eefb570170..65d20ceedc9 100644
--- a/strings/ctype-win1250ch.c
+++ b/strings/ctype-win1250ch.c
@@ -448,20 +448,25 @@ static struct wordvalue doubles[] = {
 
 static int my_strnncoll_win1250ch(CHARSET_INFO *cs __attribute__((unused)), 
 				  const uchar * s1, uint len1,
-				  const uchar * s2, uint len2)
+                                  const uchar * s2, uint len2,
+                                  my_bool s2_is_prefix)
 {
   int v1, v2;
   const uchar * p1, * p2;
   int pass1 = 0, pass2 = 0;
   int diff;
 
+  if (s2_is_prefix && len1 > len2)
+    len1=len2;
+
   p1 = s1;	p2 = s2;
 
-  do {
+  do
+  {
     NEXT_CMP_VALUE(s1, p1, pass1, v1, (int)len1);
     NEXT_CMP_VALUE(s2, p2, pass2, v2, (int)len2);
-    diff = v1 - v2;
-    if (diff != 0)		return diff;
+    if ((diff = v1 - v2))
+      return diff;
   } while (v1);
   return 0;
 }
@@ -478,7 +483,7 @@ int my_strnncollsp_win1250ch(CHARSET_INFO * cs,
 {
   for ( ; slen && s[slen-1] == ' ' ; slen--);
   for ( ; tlen && t[tlen-1] == ' ' ; tlen--);
-  return my_strnncoll_win1250ch(cs,s,slen,t,tlen);
+  return my_strnncoll_win1250ch(cs,s,slen,t,tlen,0);
 }