fix an old bug where dd_frm_type() could incorrectly determine the table type

for dynamic engines (because it only looked at the one-byte code, not at the full
engine name).

1 files changed, 55 insertions, 5 deletions

diff --git a/sql/datadict.cc b/sql/datadict.cc
index e3f679cc7ec..4e4fcafa31b 100644
--- a/sql/datadict.cc
+++ b/sql/datadict.cc
@@ -36,6 +36,7 @@ frm_type_enum dd_frm_type(THD *thd, char *path, enum legacy_db_type *dbt)
   File file;
   uchar header[10];     //"TYPE=VIEW\n" it is 10 characters
   size_t error;
+  frm_type_enum type= FRMTYPE_ERROR;
   DBUG_ENTER("dd_frm_type");
 
   *dbt= DB_TYPE_UNKNOWN;
@@ -43,12 +44,16 @@ frm_type_enum dd_frm_type(THD *thd, char *path, enum legacy_db_type *dbt)
   if ((file= mysql_file_open(key_file_frm, path, O_RDONLY | O_SHARE, MYF(0))) < 0)
     DBUG_RETURN(FRMTYPE_ERROR);
   error= mysql_file_read(file, (uchar*) header, sizeof(header), MYF(MY_NABP));
-  mysql_file_close(file, MYF(MY_WME));
 
   if (error)
-    DBUG_RETURN(FRMTYPE_ERROR);
+    goto err;
   if (!strncmp((char*) header, "TYPE=VIEW\n", sizeof(header)))
-    DBUG_RETURN(FRMTYPE_VIEW);
+  {
+    type= FRMTYPE_VIEW;
+    goto err;
+  }
+
+  type= FRMTYPE_TABLE;
 
   /*
     This is just a check for DB_TYPE. We'll return default unknown type
@@ -58,12 +63,57 @@ frm_type_enum dd_frm_type(THD *thd, char *path, enum legacy_db_type *dbt)
   if (header[0] != (uchar) 254 || header[1] != 1 ||
       (header[2] != FRM_VER && header[2] != FRM_VER+1 &&
        (header[2] < FRM_VER+3 || header[2] > FRM_VER+4)))
-    DBUG_RETURN(FRMTYPE_TABLE);
+    goto err;
 
   *dbt= (enum legacy_db_type) (uint) *(header + 3);
 
+  if (*dbt >= DB_TYPE_FIRST_DYNAMIC) /* read the true engine name */
+  {
+    MY_STAT state;  
+    uchar *frm_image= 0;
+    uint n_length;
+
+    if (mysql_file_fstat(file, &state, MYF(MY_WME)))
+      goto err;
+
+    if (mysql_file_seek(file, 0, SEEK_SET, MYF(MY_WME)))
+      goto err;
+
+    if (read_string(file, &frm_image, state.st_size))
+      goto err;
+
+    if ((n_length= uint4korr(frm_image+55)))
+    {
+      uint record_offset= (uint2korr(frm_image+6)+
+                      ((uint2korr(frm_image+14) == 0xffff ?
+                        uint4korr(frm_image+47) : uint2korr(frm_image+14))));
+      uint reclength= uint2korr(frm_image+16);
+
+      uchar *next_chunk= frm_image + record_offset + reclength;
+      uchar *buff_end= next_chunk + n_length;
+      uint connect_string_length= uint2korr(next_chunk);
+      next_chunk+= connect_string_length + 2;
+      if (next_chunk + 2 < buff_end)
+      {
+        uint str_db_type_length= uint2korr(next_chunk);
+        LEX_STRING name;
+        name.str= (char*) next_chunk + 2;
+        name.length= str_db_type_length;
+        plugin_ref tmp_plugin= ha_resolve_by_name(thd, &name);
+        if (tmp_plugin)
+          *dbt= plugin_data(tmp_plugin, handlerton *)->db_type;
+        else
+          *dbt= DB_TYPE_UNKNOWN;
+      }
+    }
+
+    my_free(frm_image);
+  }
+
   /* Probably a table. */
-  DBUG_RETURN(FRMTYPE_TABLE);
+err:
+  mysql_file_close(file, MYF(MY_WME));
+  DBUG_RETURN(type);
 }