LPBUG#983285 - incompatibility in frm in case of VIEWs with non-default ALGORITHM option.

As part of derived tables redesign, values for VIEW_ALGORITHM_MERGE and VIEW_ALGORITHM_TMPTABLE have changed from (former values 1 rsp 2 , new values 5 rsp 9).

This lead to the problem that views, created with version 5.2  or earlier would not work in all situations  (e.g "SHOW CREATE VIEW"), or with mysqldump.

The fix is to restore backward compatibility for the from file, and convert algorithm={1,2} in the frm to {5,9} when reading .frm from disk, and store backward compatible values when writing from to disk. 

Also allow processing correct processing for "invalid" .frms created with MariaDB 5.3/5.5 GA releases (where algorithm stored in memory matched the one stored in frm).

1 files changed, 48 insertions, 3 deletions

diff --git a/sql/parse_file.cc b/sql/parse_file.cc
index 3e1f254f610..761ab9ee10a 100644
--- a/sql/parse_file.cc
+++ b/sql/parse_file.cc
@@ -86,6 +86,40 @@ write_escaped_string(IO_CACHE *file, LEX_STRING *val_s)
   return FALSE;
 }
 
+static ulonglong view_algo_to_frm(ulonglong val)
+{
+  switch(val)
+  {
+    case VIEW_ALGORITHM_UNDEFINED:
+      return VIEW_ALGORITHM_UNDEFINED_FRM;
+    case VIEW_ALGORITHM_MERGE:
+      return VIEW_ALGORITHM_MERGE_FRM;
+    case VIEW_ALGORITHM_TMPTABLE:
+      return VIEW_ALGORITHM_TMPTABLE_FRM;
+  }
+  DBUG_ASSERT(0); /* Should never happen */
+  return VIEW_ALGORITHM_UNDEFINED;
+}
+
+static ulonglong view_algo_from_frm(ulonglong val)
+{
+  switch(val)
+  {
+    case VIEW_ALGORITHM_UNDEFINED_FRM:
+      return VIEW_ALGORITHM_UNDEFINED;
+    case VIEW_ALGORITHM_MERGE_FRM:
+      return VIEW_ALGORITHM_MERGE;
+    case VIEW_ALGORITHM_TMPTABLE_FRM:
+      return VIEW_ALGORITHM_TMPTABLE;
+  }
+
+  /*
+    Early versions of MariaDB 5.2/5.3 had identical in-memory and frm values
+    Return input value.
+  */
+  return val;
+}
+
 
 /**
   Write parameter value to IO_CACHE.
@@ -124,8 +158,14 @@ write_parameter(IO_CACHE *file, uchar* base, File_option *parameter)
     break;
   }
   case FILE_OPTIONS_ULONGLONG:
+  case FILE_OPTIONS_VIEW_ALGO:
   {
-    num.set(*((ulonglong *)(base + parameter->offset)), &my_charset_bin);
+    ulonglong val= *(ulonglong *)(base + parameter->offset);
+
+    if (parameter->type == FILE_OPTIONS_VIEW_ALGO)
+      val= view_algo_to_frm(val);
+
+    num.set(val, &my_charset_bin);
     if (my_b_append(file, (const uchar *)num.ptr(), num.length()))
       DBUG_RETURN(TRUE);
     break;
@@ -766,6 +806,7 @@ File_parser::parse(uchar* base, MEM_ROOT *mem_root,
 	  break;
 	}
 	case FILE_OPTIONS_ULONGLONG:
+	case FILE_OPTIONS_VIEW_ALGO:
 	  if (!(eol= strchr(ptr, '\n')))
 	  {
 	    my_error(ER_FPARSER_ERROR_IN_PARAMETER, MYF(0),
@@ -774,8 +815,12 @@ File_parser::parse(uchar* base, MEM_ROOT *mem_root,
 	  }
           {
             int not_used;
-	    *((ulonglong*)(base + parameter->offset))=
-              my_strtoll10(ptr, 0, &not_used);
+            ulonglong val= (ulonglong)my_strtoll10(ptr, 0, &not_used);
+
+            if (parameter->type == FILE_OPTIONS_VIEW_ALGO)
+              val= view_algo_from_frm(val);
+
+            *((ulonglong*)(base + parameter->offset))= val;
           }
 	  ptr= eol+1;
 	  break;