Add tests for snapshot interfaces.

FossilOrigin-Name: 1f7ee7af7b620262ae663d65889b6a87415d4a34

manifest

@@ -1,5 +1,5 @@
-C Enhance\sexisting\ssnapshot\stests\sto\sserialize/deserialize\ssnapshots.\sNo\snew\ntests.
-D 2016-11-18T14:38:41.852
+C Add\stests\sfor\ssnapshot\sinterfaces.
+D 2016-11-18T18:22:05.618
 F Makefile.in 6b572807415d3f0a379cebc9461416d8df4a12c8
 F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
 F Makefile.msc bb4d970894abbbe0e88d00aac29bd52af8bc95f4
@@ -1103,6 +1103,7 @@ F test/skipscan3.test ec5bab3f81c7038b43450e7b3062e04a198bdbb5
 F test/skipscan5.test 67817a4b6857c47e0e33ba3e506da6f23ef68de2
 F test/skipscan6.test 5866039d03a56f5bd0b3d172a012074a1d90a15b
 F test/snapshot.test bb34cc38828bf2e86a49207995fa7dfacd303832
+F test/snapshot2.test 30bd95f6fefa8be7f29421e27745cac90b66c74d
 F test/snapshot_fault.test 062ff0438a074978d45e9f9a92e7ad459b74ee73
 F test/soak.test 0b5b6375c9f4110c828070b826b3b4b0bb65cd5f
 F test/softheap1.test 843cd84db9891b2d01b9ab64cef3e9020f98d087
@@ -1534,7 +1535,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P b6a81fa1fc1fb78a65894129851a4ec3986640de
-R 17ac6d49deba8d40db4fa5f6ce7fc2ca
+P 16b9bf92741e4c62874cffd7c6a61763c5054c7a
+R aa1ba4f87ce4a1d41c6deb879752303b
 U dan
-Z cee5f11eb9093786088be3369dcd2153
+Z ee11b90501c467e7c32bf0deb14250e6

manifest.uuid

@@ -1 +1 @@
-16b9bf92741e4c62874cffd7c6a61763c5054c7a
+1f7ee7af7b620262ae663d65889b6a87415d4a34

test/snapshot2.test

@@ -0,0 +1,82 @@
+# 2016 November 18
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+# This file implements regression tests for SQLite library. The focus
+# of this file is the sqlite3_snapshot_xxx() APIs.
+#
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+ifcapable !snapshot {finish_test; return}
+set testprefix snapshot2
+
+# This test does not work with the inmemory_journal permutation. The reason
+# is that each connection opened as part of this permutation executes
+# "PRAGMA journal_mode=memory", which fails if the database is in wal mode
+# and there are one or more existing connections.
+if {[permutation]=="inmemory_journal"} {
+  finish_test
+  return
+}
+
+#-------------------------------------------------------------------------
+# Check that it is not possible to obtain a snapshot immediately after
+# a wal mode database with an empty wal file is opened. But it is after
+# the file has been written, even by some other connection.
+#
+do_execsql_test 1.0 {
+  PRAGMA journal_mode = wal;
+  CREATE TABLE t1(a, b, c);
+  INSERT INTO t1 VALUES(1, 2, 3);
+  INSERT INTO t1 VALUES(4, 5, 6);
+} {wal}
+
+db close
+do_test 1.1.1 { list [file exists test.db] [file exists test.db-wal] } {1 0}
+
+sqlite3 db test.db
+do_execsql_test 1.1.2 { SELECT * FROM t1 } {1 2 3 4 5 6}
+
+do_test 1.1.3 {
+  execsql BEGIN
+  list [catch { sqlite3_snapshot_get_blob db main } msg] $msg
+} {1 SQLITE_ERROR}
+execsql COMMIT
+
+do_test 1.1.4 {
+  execsql { INSERT INTO t1 VALUES(7, 8, 9) }
+  execsql BEGIN
+  string length [sqlite3_snapshot_get_blob db main]
+} 48
+execsql COMMIT
+
+db close
+do_test 1.2.1 { list [file exists test.db] [file exists test.db-wal] } {1 0}
+
+sqlite3 db test.db
+do_execsql_test 1.2.2 { SELECT * FROM t1 } {1 2 3 4 5 6 7 8 9}
+
+do_test 1.2.3 {
+  execsql BEGIN
+  list [catch { sqlite3_snapshot_get_blob db main } msg] $msg
+} {1 SQLITE_ERROR}
+execsql COMMIT
+
+do_test 1.2.4 {
+  sqlite3 db2 test.db
+  execsql { INSERT INTO t1 VALUES(10, 11, 12) } db2
+  execsql BEGIN
+  string length [sqlite3_snapshot_get_blob db main]
+} 48
+execsql COMMIT
+db2 close
+
+
+finish_test