Index: driver/results.c
===================================================================
--- driver/results.c	(revision 775)
+++ driver/results.c	(working copy)
@@ -531,11 +531,13 @@
       *pnColumnSize= get_column_size(stmt, field, FALSE);
     if (pibScale)
       *pibScale= max(0, get_decimal_digits(stmt, field));
-    if ( pfNullable )
-        *pfNullable= (((field->flags & (NOT_NULL_FLAG)) ==
-                       NOT_NULL_FLAG) ?
-                      SQL_NO_NULLS :
-                      SQL_NULLABLE);
+    if (pfNullable)
+      if ((field->flags & NOT_NULL_FLAG) &&
+          !(field->flags & TIMESTAMP_FLAG) &&
+          !(field->flags & AUTO_INCREMENT_FLAG))
+        *pfNullable= SQL_NO_NULLS;
+      else
+        *pfNullable= SQL_NULLABLE;
 
     if ( stmt->dbc->flag & FLAG_FULL_COLUMN_NAMES && field->table )
     {
Index: test/my_datetime.c
===================================================================
--- test/my_datetime.c	(revision 775)
+++ test/my_datetime.c	(working copy)
@@ -821,6 +821,7 @@
 DECLARE_TEST(t_bug14414)
 {
   SQLCHAR col[10];
+  SQLSMALLINT nullable;
 
   ok_sql(hstmt, "DROP TABLE IF EXISTS t_bug14414");
   ok_sql(hstmt, "CREATE TABLE t_bug14414(a TIMESTAMP, b TIMESTAMP NOT NULL,"
@@ -848,6 +849,26 @@
 
   ok_stmt(hstmt, SQLFreeStmt(hstmt, SQL_CLOSE));
 
+  /**
+    Bug #26108  MyODBC ADO field attributes reporting adFldMayBeNull for
+    not null columns
+  */
+  ok_sql(hstmt, "SELECT * FROM t_bug14414");
+
+  ok_stmt(hstmt, SQLDescribeCol(hstmt, 1, NULL, 0, NULL, NULL, NULL, NULL,
+                                &nullable));
+  is_num(nullable, SQL_NULLABLE);
+
+  ok_stmt(hstmt, SQLDescribeCol(hstmt, 2, NULL, 0, NULL, NULL, NULL, NULL,
+                                &nullable));
+  is_num(nullable, SQL_NO_NULLS);
+
+  ok_stmt(hstmt, SQLDescribeCol(hstmt, 3, NULL, 0, NULL, NULL, NULL, NULL,
+                                &nullable));
+  is_num(nullable, SQL_NULLABLE);
+
+  ok_stmt(hstmt, SQLFreeStmt(hstmt, SQL_CLOSE));
+
   ok_sql(hstmt, "DROP TABLE IF EXISTS t_bug14414");
   return OK;
 }
Index: test/my_catalog.c
===================================================================
--- test/my_catalog.c	(revision 775)
+++ test/my_catalog.c	(working copy)
@@ -1094,6 +1094,7 @@
 DECLARE_TEST(t_bug14407)
 {
   SQLCHAR col[10];
+  SQLSMALLINT nullable;
 
   ok_sql(hstmt, "DROP TABLE IF EXISTS t_bug14407");
   ok_sql(hstmt,
@@ -1111,6 +1112,18 @@
 
   ok_stmt(hstmt, SQLFreeStmt(hstmt, SQL_CLOSE));
 
+  /**
+    Bug #26108  MyODBC ADO field attributes reporting adFldMayBeNull for
+    not null columns
+  */
+  ok_sql(hstmt, "SELECT * FROM t_bug14407");
+
+  ok_stmt(hstmt, SQLDescribeCol(hstmt, 1, NULL, 0, NULL, NULL, NULL, NULL,
+                                &nullable));
+  is_num(nullable, SQL_NULLABLE);
+
+  ok_stmt(hstmt, SQLFreeStmt(hstmt, SQL_CLOSE));
+
   ok_sql(hstmt, "DROP TABLE IF EXISTS t_bug14407");
   return OK;
 }
Index: ChangeLog
===================================================================
--- ChangeLog	(revision 777)
+++ ChangeLog	(working copy)
@@ -3,6 +3,8 @@
   Functionality added or changed:
 
   Bugs fixed:
+  * SQLDescribeCol() incorrectly reported whether auto-increment and
+    some timestamp fields were nullable. (Bug #26108)
   * Empty selection for database and character set comboboxes in setup
     were set to " " instead of an empty string. (Bug #30568)