branches/innodb+: ibuf_insert_to_index_page(): When the page is empty, look

at the first deleted record when checking the number of fields.
This fixes part of Issue #82.

ibuf/ibuf0ibuf.c

@@ -3330,6 +3330,20 @@ ibuf_insert_to_index_page(
 
 	rec = page_rec_get_next(page_get_infimum_rec(page));
 
+	if (page_rec_is_supremum(rec)) {
+		/* Empty pages can result from buffered delete operations.
+		The first record from the free list can be used to find the
+		father node. */
+		rec = page_header_get_ptr(page, PAGE_FREE);
+		if (UNIV_UNLIKELY(rec == NULL)) {
+			fputs("InnoDB: Trying to insert a record from"
+			      " the insert buffer to an index page\n"
+			      "InnoDB: but the index page is empty!\n",
+			      stderr);
+			goto dump;
+		}
+	}
+
 	if (UNIV_UNLIKELY(rec_get_n_fields(rec, index)
 			  != dtuple_get_n_fields(entry))) {
 		fputs("InnoDB: Trying to insert a record from"