[fireball] 44285: [ntoskrnl/cm] - CmpSelectLeaf fixes: looking into an incorrect cell, returning wrong cell, slightly simplify code and add more comments for clarity. Thanks to Michael Martin for spotting these bugs.

Author: fireball
Date: Tue Nov 24 23:56:43 2009
New Revision: 44285

URL: http://svn.reactos.org/svn/reactos?rev=44285&view=rev
Log:
[ntoskrnl/cm]
- CmpSelectLeaf fixes: looking into an incorrect cell, returning wrong cell, slightly simplify code and add more comments for clarity. Thanks to Michael Martin for spotting these bugs.

Modified:
    trunk/reactos/ntoskrnl/config/cmindex.c

Modified: trunk/reactos/ntoskrnl/config/cmindex.c
URL: http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/config/cmindex.c?r...
==============================================================================
--- trunk/reactos/ntoskrnl/config/cmindex.c [iso-8859-1] (original)
+++ trunk/reactos/ntoskrnl/config/cmindex.c [iso-8859-1] Tue Nov 24 23:56:43 2009
@@ -1344,6 +1344,8 @@
                 *RootCell = &IndexKey->List[SubKeyIndex];
                 return LeafCell;
             }
+
+            /* It didn't fit, so proceed to splitting */
         }
         else
         {
@@ -1380,22 +1382,22 @@
             /* Check if it's above */
             if (Result >= 0)
             {
-                /* Get the first cell in the index */
-                LeafCell = IndexKey->List[0];
+                /* Get the cell in the index */
+                LeafCell = IndexKey->List[SubKeyIndex];
                 LeafKey = (PCM_KEY_INDEX)HvGetCell(Hive, LeafCell);

/* Return an error in case of problems */
                 if (!LeafKey) return HCELL_NIL;

-                /* Check if it fits into this leaf and break */
+                /* Check if it fits into this leaf */
                 if (LeafKey->Count < CmpMaxIndexPerHblock)
                 {
                     /* Fill in the result and return the cell */
-                    *RootCell = &IndexKey->List[SubKeyIndex + 1];
+                    *RootCell = &IndexKey->List[SubKeyIndex];
                     return LeafCell;
                 }

-                /* No, it doesn't fit, check the other leaf */
+                /* No, it doesn't fit, check the next adjacent leaf */
                 if (SubKeyIndex < (IndexKey->Count - 1))
                 {
                     /* Yes, there is space */
@@ -1413,6 +1415,8 @@
                         return LeafCell;
                     }
                 }
+
+                /* It didn't fit, so proceed to splitting */
             }
             else
             {
@@ -1429,11 +1433,8 @@
                     /* Check if it fits and break */
                     if (LeafKey->Count < CmpMaxIndexPerHblock)
                     {
-                        /* Decrement the subkey index */
-                        SubKeyIndex--;
-
                         /* Fill in the result and return the cell */
-                        *RootCell = &IndexKey->List[SubKeyIndex];
+                        *RootCell = &IndexKey->List[SubKeyIndex - 1];
                         return LeafCell;
                     }
                 }