Bug#13523839 ASSERTION FAILURES ON COMPRESSED INNODB TABLES

btr_cur_optimistic_insert(): Remove a bogus assertion. The insert may
fail after reorganizing the page.

btr_cur_optimistic_update(): Do not attempt to reorganize compressed pages,
because compression may fail after reorganization.

page_copy_rec_list_start(): Use page_rec_get_nth() to restore to the
ret_pos, which may also be the page infimum.

rb:1221

storage/innodb_plugin/ChangeLog

+2012-08-16	The InnoDB Team
+
+	* btr/btr0cur.c, page/page0page.c:
+	Fix Bug#13523839 ASSERTION FAILURES ON COMPRESSED INNODB TABLES
+
 2012-08-07	The InnoDB Team
 
 	* btr/btr0pcur.c, row/row0merge.c:

storage/innodb_plugin/btr/btr0cur.c

@@ -1220,7 +1220,12 @@ fail_err:
 
 		if (UNIV_UNLIKELY(reorg)) {
 			ut_a(zip_size);
-			ut_a(*rec);
+			/* It's possible for rec to be NULL if the
+			page is compressed.  This is because a
+			reorganized page may become incompressible. */
+			if (!*rec) {
+				goto fail;
+			}
 		}
 	}
 
@@ -1973,8 +1978,12 @@ any_extern:
 		goto err_exit;
 	}
 
-	max_size = old_rec_size
-		+ page_get_max_insert_size_after_reorganize(page, 1);
+	/* We do not attempt to reorganize if the page is compressed.
+	This is because the page may fail to compress after reorganization. */
+	max_size = page_zip
+		? page_get_max_insert_size(page, 1)
+		: (old_rec_size
+		   + page_get_max_insert_size_after_reorganize(page, 1));
 
 	if (!(((max_size >= BTR_CUR_PAGE_REORGANIZE_LIMIT)
 	       && (max_size >= new_rec_size))

storage/innodb_plugin/page/page0page.c

@@ -780,12 +780,18 @@ page_copy_rec_list_start(
 	if (UNIV_LIKELY_NULL(new_page_zip)) {
 		mtr_set_log_mode(mtr, log_mode);
 
+		DBUG_EXECUTE_IF("page_copy_rec_list_start_compress_fail",
+				goto zip_reorganize;);
+
 		if (UNIV_UNLIKELY
 		    (!page_zip_compress(new_page_zip, new_page, index, mtr))) {
+			ulint	ret_pos;
+#ifndef DBUG_OFF
+zip_reorganize:
+#endif /* DBUG_OFF */
 			/* Before trying to reorganize the page,
 			store the number of preceding records on the page. */
-			ulint	ret_pos
-				= page_rec_get_n_recs_before(ret);
+			ret_pos = page_rec_get_n_recs_before(ret);
 			/* Before copying, "ret" was the predecessor
 			of the predefined supremum record.  If it was
 			the predefined infimum record, then it would
@@ -806,15 +812,10 @@ page_copy_rec_list_start(
 				btr_blob_dbg_add(new_page, index,
 						 "copy_start_reorg_fail");
 				return(NULL);
-			} else {
-				/* The page was reorganized:
-				Seek to ret_pos. */
-				ret = new_page + PAGE_NEW_INFIMUM;
-
-				do {
-					ret = rec_get_next_ptr(ret, TRUE);
-				} while (--ret_pos);
 			}
+
+			/* The page was reorganized: Seek to ret_pos. */
+			ret = page_rec_get_nth(new_page, ret_pos);
 		}
 	}