branches/zip: Improve the diagnostics for tracking down issue#63 and issue#65.

buf_flush_init_for_writing(), buf_LRU_block_remove_hashed_page():
Dump the page frame featuring the incorrect FIL_PAGE_TYPE along with the
page_zip->data that might contain an earlier version of the page.

buf/buf0flu.c

@@ -638,6 +638,8 @@ buf_flush_init_for_writing(
 		ut_print_timestamp(stderr);
 		fputs("  InnoDB: ERROR: The compressed page to be written"
 		      " seems corrupt:", stderr);
+		ut_print_buf(stderr, page, zip_size);
+		fputs("\nInnoDB: Possibly older version of the page:", stderr);
 		ut_print_buf(stderr, page_zip->data, zip_size);
 		putc('\n', stderr);
 		ut_error;

buf/buf0lru.c

@@ -1455,6 +1455,8 @@ buf_LRU_block_remove_hashed_page(
 		buf_block_modify_clock_inc((buf_block_t*) bpage);
 		if (bpage->zip.data) {
 			const page_t*	page = ((buf_block_t*) bpage)->frame;
+			const ulint	zip_size
+				= page_zip_get_size(&bpage->zip);
 
 			ut_a(!zip || bpage->oldest_modification == 0);
 
@@ -1472,7 +1474,7 @@ buf_LRU_block_remove_hashed_page(
 					to the compressed page, which will
 					be preserved. */
 					memcpy(bpage->zip.data, page,
-					       page_zip_get_size(&bpage->zip));
+					       zip_size);
 				}
 				break;
 			case FIL_PAGE_TYPE_ZBLOB:
@@ -1487,8 +1489,11 @@ buf_LRU_block_remove_hashed_page(
 				ut_print_timestamp(stderr);
 				fputs("  InnoDB: ERROR: The compressed page"
 				      " to be evicted seems corrupt:", stderr);
+				ut_print_buf(stderr, page, zip_size);
+				fputs("\nInnoDB: Possibly older version"
+				      " of the page:", stderr);
 				ut_print_buf(stderr, bpage->zip.data,
-					     page_zip_get_size(&bpage->zip));
+					     zip_size);
 				putc('\n', stderr);
 				ut_error;
 			}