test-custom-filter: heredoc is not required for single line operations

tests/test-custom-filters.t

@@ -1,69 +1,65 b''
   $ hg init
 
   $ cat > .hg/hgrc <<EOF
   > [extensions]
   > prefixfilter = prefix.py
   > [encode]
   > *.txt = stripprefix: Copyright 2046, The Masters
   > [decode]
   > *.txt = insertprefix: Copyright 2046, The Masters
   > EOF
 
   $ cat > prefix.py <<EOF
   > from mercurial import util
   > def stripprefix(s, cmd, filename, **kwargs):
   >     header = '%s\n' % cmd
   >     if s[:len(header)] != header:
   >         raise util.Abort('missing header "%s" in %s' % (cmd, filename))
   >     return s[len(header):]
   > def insertprefix(s, cmd):
   >     return '%s\n%s' % (cmd, s)
   > def reposetup(ui, repo):
   >     repo.adddatafilter('stripprefix:', stripprefix)
   >     repo.adddatafilter('insertprefix:', insertprefix)
   > EOF
 
   $ cat > .hgignore <<EOF
   > .hgignore
   > prefix.py
   > prefix.pyc
   > EOF
 
   $ cat > stuff.txt <<EOF
   > Copyright 2046, The Masters
   > Some stuff to ponder very carefully.
   > EOF
   $ hg add stuff.txt
   $ hg ci -m stuff
 
 Repository data:
 
   $ hg cat stuff.txt
   Some stuff to ponder very carefully.
 
 Fresh checkout:
 
   $ rm stuff.txt
   $ hg up -C
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ cat stuff.txt
   Copyright 2046, The Masters
   Some stuff to ponder very carefully.
-  $ echo >> stuff.txt <<EOF
-  > Very very carefully.
-  > EOF
+  $ echo "Very very carefully." >> stuff.txt
   $ hg stat
   M stuff.txt
 
-  $ cat > morestuff.txt <<EOF
-  > Unauthorized material subject to destruction.
-  > EOF
+  $ echo "Unauthorized material subject to destruction." > morestuff.txt
 
 Problem encoding:
 
   $ hg add morestuff.txt
   $ hg ci -m morestuff
   abort: missing header "Copyright 2046, The Masters" in morestuff.txt
   $ hg stat
   M stuff.txt
   A morestuff.txt