1 files changed, 68 insertions, 3 deletions

diff --git a/myisam/ft_update.c b/myisam/ft_update.c
index 658ea9282f3..f8f1d7769aa 100644
--- a/myisam/ft_update.c
+++ b/myisam/ft_update.c
@@ -29,14 +29,16 @@
 
 
 /* parses a document i.e. calls _mi_ft_parse for every keyseg */
-static FT_WORD * _mi_ft_parserecord(MI_INFO *info, uint keynr, byte *keybuf,
+FT_WORD * _mi_ft_parserecord(MI_INFO *info, uint keynr, byte *keybuf,
 				    const byte *record)
 {
-  TREE *parsed=NULL;
+  TREE *parsed, ptree;
   MI_KEYSEG *keyseg;
   byte *pos;
   uint i;
 
+  bzero(parsed=&ptree, sizeof(ptree));
+
   keyseg=info->s->keyinfo[keynr].seg;
   for (i=info->s->keyinfo[keynr].keysegs-FT_SEGS ; i-- ; )
   {
@@ -64,7 +66,7 @@ static FT_WORD * _mi_ft_parserecord(MI_INFO *info, uint keynr, byte *keybuf,
       return NULL;
   }
   /* Handle the case where all columns are NULL */
-  if (!parsed && !(parsed=ft_parse(0, (byte*) "", 0)))
+  if (!is_tree_inited(parsed) && !(parsed=ft_parse(parsed, (byte*) "", 0)))
     return NULL;
   return ft_linearize(info, keynr, keybuf, parsed);
 }
@@ -151,6 +153,69 @@ int _mi_ft_cmp(MI_INFO *info, uint keynr, const byte *rec1, const byte *rec2)
   return GEE_THEY_ARE_ABSOLUTELY_IDENTICAL;
 }
 
+/* update a document entry */
+int _mi_ft_update(MI_INFO *info, uint keynr, byte *keybuf, 
+                  const byte *oldrec, const byte *newrec, my_off_t pos)
+{
+  int error= -1;
+  FT_WORD *oldlist,*newlist, *old_word, *new_word;
+  uint key_length;
+  uint cmp;
+
+  if (!(old_word=oldlist=_mi_ft_parserecord(info, keynr, keybuf, oldrec)))
+    goto err0;
+  if (!(new_word=newlist=_mi_ft_parserecord(info, keynr, keybuf, newrec)))
+    goto err1;
+
+  while(old_word->pos && new_word->pos)
+  {
+    cmp=_mi_compare_text(default_charset_info,
+	                 (uchar*) old_word->pos,old_word->len,
+			 (uchar*) new_word->pos,new_word->len,0);
+    if (cmp==0)
+    {
+      double p=(old_word->weight-new_word->weight)/
+               (old_word->weight+new_word->weight);
+      if (p<1e-5)
+        cmp=0;
+      else
+        cmp=sgn(p);
+    }
+    else
+      cmp=sgn(cmp);
+
+    switch (cmp) {
+    case -1:
+      key_length=_ft_make_key(info,keynr,keybuf,old_word,pos);
+      if (error=_mi_ck_delete(info,keynr,(uchar*) keybuf,key_length))
+        goto err2;
+      old_word++;
+      break;
+    case 0:
+      old_word++;
+      new_word++;
+      break;
+    case 1:
+      key_length=_ft_make_key(info,keynr,keybuf,new_word,pos);
+      if (error=_mi_ck_write(info,keynr,(uchar*) keybuf,key_length))
+        goto err2;
+      new_word++;
+      break;
+   }
+ }
+ if (old_word->pos)
+   error=_mi_ft_erase(info,keynr,keybuf,old_word,pos);
+ else if (new_word->pos)
+   error=_mi_ft_store(info,keynr,keybuf,new_word,pos);
+
+err2:
+    my_free((char*) newlist,MYF(0));
+err1:
+    my_free((char*) oldlist,MYF(0));
+err0:
+  return error;
+}
+
 /* adds a document to the collection */
 int _mi_ft_add(MI_INFO *info, uint keynr, byte *keybuf, const byte *record,
 	       my_off_t pos)