Import SQLite 3.7.6.3.

third_party/sqlite/src/test/incrvacuum2.test

Index: third_party/sqlite/src/test/incrvacuum2.test
diff --git a/third_party/sqlite/src/test/incrvacuum2.test b/third_party/sqlite/src/test/incrvacuum2.test
index d8a391b7136ae435adc9988d7ede7da50b6e1baf..902517c9494e13570ff8bae7827ca0706f5e81d2 100644
--- a/third_party/sqlite/src/test/incrvacuum2.test
+++ b/third_party/sqlite/src/test/incrvacuum2.test
@@ -23,6 +23,7 @@ ifcapable {!autovacuum || !pragma} {
   return
 }
 
+set testprefix incrvacuum2
 
 # Create a database in incremental vacuum mode that has many
 # pages on the freelist.
@@ -131,6 +132,80 @@ do_test incrvacuum2-3.2 {
   }
 } {}
 
-integrity_check incremental2-3.3
+integrity_check incrvacuum2-3.3
+
+ifcapable wal {
+  # At one point, when a specific page was being extracted from the b-tree
+  # free-list (e.g. during an incremental-vacuum), all trunk pages that
+  # occurred before the specific page in the free-list trunk were being
+  # written to the journal or wal file. This is not necessary. Only the 
+  # extracted page and the page that contains the pointer to it need to
+  # be journalled.
+  #
+  # This problem was fixed by [d03d63d77e] (just before 3.7.6 release).
+  #
+  # This test case builds a database containing many free pages. Then runs
+  # "PRAGMA incremental_vacuum(1)" until the db contains zero free pages.
+  # Each "PRAGMA incremental_vacuum(1)" should modify at most 4 pages. The
+  # worst case is when a trunk page is removed from the end of the db file.
+  # In this case pages written are:
+  #
+  #   1. The previous trunk page (that contains a pointer to the recycled
+  #      trunk page), and
+  #   2. The leaf page transformed into a trunk page to replace the recycled
+  #      page, and
+  #   3. The trunk page that contained a pointer to the leaf page used 
+  #      in (2), and
+  #   4. Page 1. Page 1 is always updated, even in WAL mode, since it contains
+  #      the "number of free-list pages" field.
+  #
+  db close
+  forcedelete test.db
+  sqlite3 db test.db
+
+  do_execsql_test 4.1 {
+    PRAGMA page_size = 512;
+    PRAGMA auto_vacuum = 2;
+    CREATE TABLE t1(x);
+    INSERT INTO t1 VALUES(randomblob(400));
+    INSERT INTO t1 SELECT * FROM t1;            --    2
+    INSERT INTO t1 SELECT * FROM t1;            --    4
+    INSERT INTO t1 SELECT * FROM t1;            --    8
+    INSERT INTO t1 SELECT * FROM t1;            --   16
+    INSERT INTO t1 SELECT * FROM t1;            --   32
+    INSERT INTO t1 SELECT * FROM t1;            --  128
+    INSERT INTO t1 SELECT * FROM t1;            --  256
+    INSERT INTO t1 SELECT * FROM t1;            --  512
+    INSERT INTO t1 SELECT * FROM t1;            -- 1024
+    INSERT INTO t1 SELECT * FROM t1;            -- 2048
+    INSERT INTO t1 SELECT * FROM t1;            -- 4096
+    INSERT INTO t1 SELECT * FROM t1;            -- 8192
+    DELETE FROM t1 WHERE oid>512;
+    DELETE FROM t1;
+  }
+
+  do_test 4.2 {
+    execsql { 
+      PRAGMA journal_mode = WAL;
+      PRAGMA incremental_vacuum(1);
+      PRAGMA wal_checkpoint;
+    }
+    file size test.db-wal
+  } {1640}
+
+  do_test 4.3 {
+    db close
+    sqlite3 db test.db
+    set maxsz 0
+    while {[file size test.db] > [expr 512*3]} {
+      execsql { PRAGMA journal_mode = WAL }
+      execsql { PRAGMA wal_checkpoint }
+      execsql { PRAGMA incremental_vacuum(1) }
+      set newsz [file size test.db-wal]
+      if {$newsz>$maxsz} {set maxsz $newsz}
+    }
+    set maxsz 
+  } {2176}
+}
 
 finish_test