test/symlink.test

# 2015 October 31
#
# 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 testing that SQLite can follow symbolic links.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
set testprefix symlink

# This only runs on unix.
if {$::tcl_platform(platform)!="unix"} {
  finish_test
  return
}

# Ensure that test.db has been created.
#
do_execsql_test 1.0 {
  CREATE TABLE t1(x, y);
}

# Test that SQLite follows symlinks when opening files.
#
forcedelete test.db2
do_test 1.1 {
  file link test.db2 test.db
  sqlite3 db2 test.db2
  sqlite3_db_filename db2 main
} [file join [pwd] test.db]

# But not with the -nofollow flag
#
do_test 1.1.2 {
  db2 close
  set rc [catch {sqlite3 db2 test.db2 -nofollow 1} msg]
  lappend rc $msg
} {1 {unable to open database file}}

# If the main database is successfully opened with -nofollow, then -nofollow
# is also used for ATTACH.
#
do_test 1.1.3 {
  catch {db2 close}
  sqlite3 db2 test.db -nofollow 1
} {}
do_test 1.1.4 {
  catchsql {ATTACH 'test.db2' AS aux1;} db2
} {1 {unable to open database: test.db2}}

# Test that if the symlink points to a file that does not exists, it is
# created when it is opened.
#
do_test 1.2.1 {
  catch {db2 close}
  db close
  forcedelete test.db
  file exists test.db
} 0
do_test 1.2.2 {
  sqlite3 db2 test.db2
  file exists test.db
} 1
do_test 1.2.3 {
  sqlite3_db_filename db2 main
} [file join [pwd] test.db]
db2 close

# Test that a loop of symlinks cannot be opened.
#
do_test 1.3 {
  forcedelete test.db
  # Note: Tcl [file link] command is too smart to create loops of symlinks.
  exec ln -s test.db2 test.db
  list [catch { sqlite3 db test.db } msg] $msg
} {1 {unable to open database file}}

# Test that overly large paths cannot be opened.
#
do_test 1.4 {
  set name "test.db[string repeat x 502]"
  list [catch { sqlite3 db $name } msg] $msg
} {1 {unable to open database file}}
do_test 1.5 {
  set r [expr 510 - [string length test.db] - [string length [pwd]]]
  set name "test.db[string repeat x $r]"
  list [catch { sqlite3 db $name } msg] $msg
} {1 {unable to open database file}}

#-------------------------------------------------------------------------
# Test that journal and wal files are created next to the real file,
# not the symlink.
#
do_test 2.0 {
  catch { db close }
  catch { db2 close }
  forcedelete test.db test.db2 test.db3
  sqlite3 db test.db
  execsql { CREATE TABLE t1(x) }
  file link test.db2 test.db
  file link test.db3 test.db2
  set {} {}
} {}

foreach {tn f} {1 test.db2 2 test.db3} {
  do_test 2.$tn.1 {
    sqlite3 db2 $f
    file exists test.db-journal
  } 0
  do_test 2.$tn.2 {
    execsql {
      BEGIN;
        INSERT INTO t1 VALUES(1);
    } db2
    file exists test.db-journal
  } [expr [atomic_batch_write test.db]==0]
  do_test 2.$tn.3 {
    list [file exists test2.db-journal] [file exists test3.db-journal]
  } {0 0}
  do_test 2.$tn.4 {
    execsql {
      COMMIT;
      PRAGMA journal_mode = wal;
      INSERT INTO t1 VALUES(2);
    } db2
    file exists test.db-wal
  } 1
  do_test 2.$tn.5 {
    list [file exists test2.db-wal] [file exists test3.db-wal]
  } {0 0}
  do_execsql_test 2.$tn.6 {
    SELECT * FROM t1;
  } {1 2}
  db2 close
  do_execsql_test 2.$tn.7 {
    DELETE FROM t1;
    PRAGMA journal_mode = delete;
  } delete
}

# Try to open a ridiculously long pathname.  Bug found by
# Kostya Serebryany using libFuzzer on 2015-11-30.
#
do_test 3.1 {
  db close
  catch {sqlite3 db [string repeat [string repeat x 100]/ 6]} res
  set res
} {unable to open database file}

#-------------------------------------------------------------------------
# Test that relative symlinks that are not located in the cwd work.
#
do_test 4.1 {
  forcedelete x y z
  file mkdir x
  file mkdir y
  file mkdir z
  sqlite3 db x/test.db
  file link y/test.db ../x/test.db
  file link z/test.db ../y/test.db
  execsql {
    PRAGMA journal_mode = wal;
    CREATE TABLE t1(x, y);
    INSERT INTO t1 VALUES('hello', 'world');
  }
} {wal}

do_test 4.2.1 {
  db close
  sqlite3 db y/test.db
  db eval { SELECT * FROM t1 }
} {hello world}
do_test 4.2.2 {
  list [file exists x/test.db-wal] [file exists y/test.db-wal]
} {1 0}

do_test 4.3.1 {
  db close
  sqlite3 db z/test.db
  db eval { SELECT * FROM t1 }
} {hello world}
do_test 4.3.2 {
  list [file exists x/test.db-wal] [file exists y/test.db-wal] \
       [file exists z/test.db-wal]
} {1 0 0}

do_test 4.4.0 {
  forcedelete w
  file mkdir w
  file link w/test.db [file join [pwd] x/test.db] 
  set {} {}
} {}
do_test 4.4.1 {
  db close
  sqlite3 db w/test.db
  db eval { SELECT * FROM t1 }
} {hello world}
do_test 4.4.2 {
  list [file exists x/test.db-wal] [file exists w/test.db-wal]
} {1 0}

finish_test