patch 8.0.0645: no error for illegal back reference in NFA engine
Problem: The new regexp engine does not give an error for using a back
reference where it is not allowed. (Dominique Pelle)
Solution: Check the back reference like the old engine. (closes #1774)
diff --git a/src/regexp.c b/src/regexp.c
index 74a73c4..7304bd3 100644
--- a/src/regexp.c
+++ b/src/regexp.c
@@ -1294,6 +1294,34 @@
return p;
}
+/*
+ * Return TRUE if the back reference is legal. We must have seen the close
+ * brace.
+ * TODO: Should also check that we don't refer to something that is repeated
+ * (+*=): what instance of the repetition should we match?
+ */
+ static int
+seen_endbrace(int refnum)
+{
+ if (!had_endbrace[refnum])
+ {
+ char_u *p;
+
+ /* Trick: check if "@<=" or "@<!" follows, in which case
+ * the \1 can appear before the referenced match. */
+ for (p = regparse; *p != NUL; ++p)
+ if (p[0] == '@' && p[1] == '<' && (p[2] == '!' || p[2] == '='))
+ break;
+ if (*p == NUL)
+ {
+ EMSG(_("E65: Illegal back reference"));
+ rc_did_emsg = TRUE;
+ return FALSE;
+ }
+ }
+ return TRUE;
+}
+
static regprog_T *bt_regcomp(char_u *expr, int re_flags);
static void bt_regfree(regprog_T *prog);
@@ -2099,24 +2127,8 @@
int refnum;
refnum = c - Magic('0');
- /*
- * Check if the back reference is legal. We must have seen the
- * close brace.
- * TODO: Should also check that we don't refer to something
- * that is repeated (+*=): what instance of the repetition
- * should we match?
- */
- if (!had_endbrace[refnum])
- {
- /* Trick: check if "@<=" or "@<!" follows, in which case
- * the \1 can appear before the referenced match. */
- for (p = regparse; *p != NUL; ++p)
- if (p[0] == '@' && p[1] == '<'
- && (p[2] == '!' || p[2] == '='))
- break;
- if (*p == NUL)
- EMSG_RET_NULL(_("E65: Illegal back reference"));
- }
+ if (!seen_endbrace(refnum))
+ return NULL;
ret = regnode(BACKREF + refnum);
}
break;
diff --git a/src/regexp_nfa.c b/src/regexp_nfa.c
index 5ba80f2..804d742 100644
--- a/src/regexp_nfa.c
+++ b/src/regexp_nfa.c
@@ -1446,8 +1446,14 @@
case Magic('7'):
case Magic('8'):
case Magic('9'):
- EMIT(NFA_BACKREF1 + (no_Magic(c) - '1'));
- nfa_has_backref = TRUE;
+ {
+ int refnum = no_Magic(c) - '1';
+
+ if (!seen_endbrace(refnum + 1))
+ return FAIL;
+ EMIT(NFA_BACKREF1 + refnum);
+ nfa_has_backref = TRUE;
+ }
break;
case Magic('z'):
diff --git a/src/testdir/test_hlsearch.vim b/src/testdir/test_hlsearch.vim
index b934d38..e9790bb 100644
--- a/src/testdir/test_hlsearch.vim
+++ b/src/testdir/test_hlsearch.vim
@@ -38,11 +38,11 @@
return
endif
- " This pattern takes forever to match, it should timeout.
+ " This pattern takes a long time to match, it should timeout.
help
let start = reltime()
set hlsearch nolazyredraw redrawtime=101
- let @/ = '\%#=2\v(a|\1)*'
+ let @/ = '\%#=1a*.*X\@<=b*'
redraw
let elapsed = reltimefloat(reltime(start))
call assert_true(elapsed > 0.1)
diff --git a/src/testdir/test_regexp_latin.vim b/src/testdir/test_regexp_latin.vim
index 247e5e6..a8fa64d 100644
--- a/src/testdir/test_regexp_latin.vim
+++ b/src/testdir/test_regexp_latin.vim
@@ -62,3 +62,13 @@
call assert_equal(expected, actual)
endfor
endfunc
+
+func Test_backref()
+ new
+ call setline(1, ['one', 'two', 'three', 'four', 'five'])
+ call assert_equal(3, search('\%#=1\(e\)\1'))
+ call assert_equal(3, search('\%#=2\(e\)\1'))
+ call assert_fails('call search("\\%#=1\\(e\\1\\)")', 'E65:')
+ call assert_fails('call search("\\%#=2\\(e\\1\\)")', 'E65:')
+ bwipe!
+endfunc
diff --git a/src/testdir/test_statusline.vim b/src/testdir/test_statusline.vim
index cf85bd5..351b119 100644
--- a/src/testdir/test_statusline.vim
+++ b/src/testdir/test_statusline.vim
@@ -223,7 +223,7 @@
set statusline=ab%(cd%q%)de
call assert_match('^abde\s*$', s:get_statusline())
copen
- call assert_match('^abcd\[Quickfix List\1]de\s*$', s:get_statusline())
+ call assert_match('^abcd\[Quickfix List]de\s*$', s:get_statusline())
cclose
" %#: Set highlight group. The name must follow and then a # again.
diff --git a/src/version.c b/src/version.c
index 24bb820..2c3c45a 100644
--- a/src/version.c
+++ b/src/version.c
@@ -765,6 +765,8 @@
static int included_patches[] =
{ /* Add new patch number below this line */
/**/
+ 645,
+/**/
644,
/**/
643,