commit b2fb272e44f459de312c07090347af9fa8165b08
Author: nizamordulu <nizamordulu@fb.com>
Date:   2 days ago

    Fix the bugs revealed by simulate_comp_failures test.
    
    Summary: This diff fixes the bugs revealed by the simulate_comp_failures test
    
    Test Plan: OK
    
    Reviewers: mcallaghan
    
    CC: db-eng@lists
    
    Differential Revision: https://phabricator.fb.com/D382730
    
    Revert Plan: ok
    
    Task ID: 855216

diff --git a/storage/innodb_plugin/btr/btr0cur.c b/storage/innodb_plugin/btr/btr0cur.c
index cd820e3..9112cf1 100644
--- a/storage/innodb_plugin/btr/btr0cur.c
+++ b/storage/innodb_plugin/btr/btr0cur.c
@@ -1226,7 +1226,10 @@ 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;
 		}
 	}
 
@@ -2022,8 +2025,11 @@ any_extern:
 		goto err_exit;
 	}
 
+	/* We do not attempt to reorganize if the page is compressed.
+	   This is because the page may fail to compress after reorganization */
 	max_size = old_rec_size
-		+ page_get_max_insert_size_after_reorganize(page, 1);
+		+ (page_zip ? page_get_max_insert_size(page, 1)
+		            : page_get_max_insert_size_after_reorganize(page, 1));
 
 	if (!(((max_size >= BTR_CUR_PAGE_REORGANIZE_LIMIT)
 	       && (max_size >= new_rec_size))
@@ -2384,7 +2390,10 @@ make_external:
 		err = DB_SUCCESS;
 		goto return_after_reservations;
 	} else {
-		ut_a(optim_err != DB_UNDERFLOW);
+		/* If the page is compressed, it is possible for btr_cur_optimistic_update()
+		   to return DB_UNDERFLOW and btr_cur_insert_if_possible() to return FALSE.
+		   See http://bugs.mysql.com/bug.php?id=61208 */
+		ut_a(page_zip || optim_err != DB_UNDERFLOW);
 
 		/* Out of space: reset the free bits. */
 		if (!dict_index_is_clust(index)
diff --git a/storage/innodb_plugin/page/page0page.c b/storage/innodb_plugin/page/page0page.c
index 91ac5e8..b3d9036 100644
--- a/storage/innodb_plugin/page/page0page.c
+++ b/storage/innodb_plugin/page/page0page.c
@@ -817,10 +817,12 @@ page_copy_rec_list_start(
 				/* The page was reorganized:
 				Seek to ret_pos. */
 				ret = new_page + PAGE_NEW_INFIMUM;
-
-				do {
+				/* ret_pos may be zero */
+				while (ret_pos) {
+					ut_a(ret);
 					ret = rec_get_next_ptr(ret, TRUE);
-				} while (--ret_pos);
+					--ret_pos;
+				}
 			}
 		}
 	}