Add a test to verify that 3.6.17 releases read-locks obtained to read the database schema even if the connection is not currently in auto-commit mode.

FossilOrigin-Name: 78dfe8321db9debfcd4a7f3daf4223d0cbf23ab9

test/lock7.test

@@ -0,0 +1,61 @@
+# 2009 August 17
+#
+# 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.
+#
+#***********************************************************************
+#
+# Check that reading the database schema from within an active transaction
+# does not establish a SHARED lock on the database file if one is not
+# already held (or, more accurately, that the SHARED lock is released after
+# reading the database schema).
+#
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+
+do_test lock7-1.1 {
+  execsql { CREATE TABLE t1(a, b) }
+  db close
+
+  sqlite3 db1 test.db
+  sqlite3 db2 test.db
+
+  db1 eval {BEGIN}
+  db2 eval {BEGIN}
+} {}
+
+do_test lock7-1.2 {
+  execsql { PRAGMA lock_status } db1
+} {main unlocked temp closed}
+do_test lock7-1.3 {
+  execsql { PRAGMA lock_status } db2
+} {main unlocked temp closed}
+
+do_test lock7-1.4 {
+  catchsql { INSERT INTO t1 VALUES(1, 1) } db1
+} {0 {}}
+do_test lock7-1.5 {
+  catchsql { INSERT INTO t1 VALUES(2, 2) } db2
+} {1 {database is locked}}
+
+do_test lock7-1.6 {
+  execsql { PRAGMA lock_status } db1
+} {main reserved temp closed}
+do_test lock7-1.7 {
+  execsql { PRAGMA lock_status } db2
+} {main unlocked temp closed}
+
+do_test lock7-1.8 {
+  execsql { COMMIT } db1
+} {}
+
+db1 close
+db2 close
+
+finish_test
+