From 1b22722ed769d7f53d3e0f6e21962d38b4a7f3df Mon Sep 17 00:00:00 2001
From: Norihiro Tanaka <address@hidden>
Date: Fri, 11 Apr 2014 21:34:11 +0900
Subject: [PATCH] grep: no match for the empty string included in multiple
 patterns

* src/dfasearch.c (EGAcompile): Fix it.
* src/kwsearch.c (Fcompile): Fix it.
---
 src/dfasearch.c   | 11 +++++++++++
 src/kwsearch.c    | 47 ++++++++++++++++++++++++-----------------------
 tests/Makefile.am |  1 +
 tests/empty-line  | 17 +++++++++++++++++
 4 files changed, 53 insertions(+), 23 deletions(-)
 create mode 100755 tests/empty-line

diff --git a/src/dfasearch.c b/src/dfasearch.c
index 2ae0a4a..39ea442 100644
--- a/src/dfasearch.c
+++ b/src/dfasearch.c
@@ -152,6 +152,17 @@ GEAcompile (char const *pattern, size_t size, reg_syntax_t syntax_bits)
       p = sep;
     } while (sep && total != 0);
 
+  if (sep)
+    {
+      patterns = xnrealloc (patterns, pcount + 1, sizeof *patterns);
+      patterns[pcount] = patterns0;
+
+      if ((err = re_compile_pattern ("", 0,
+                                    &(patterns[pcount].regexbuf))) != NULL)
+        error (EXIT_TROUBLE, 0, "%s", err);
+      pcount++;
+    }
+
   /* In the match_words and match_lines cases, we use a different pattern
      for the DFA matcher that will quickly throw out cases that won't work.
      Then if DFA succeeds we do some hairy stuff using the regex matcher
diff --git a/src/kwsearch.c b/src/kwsearch.c
index df94951..7fe8e48 100644
--- a/src/kwsearch.c
+++ b/src/kwsearch.c
@@ -32,42 +32,43 @@ static kwset_t kwset;
 void
 Fcompile (char const *pattern, size_t size)
 {
-  size_t psize = size;
+  char const *p, *sep;
+  size_t total = size;
   mb_len_map_t *map = NULL;
   char const *pat = (match_icase && MB_CUR_MAX > 1
-                     ? mbtoupper (pattern, &psize, &map)
+                     ? mbtoupper (pattern, &total, &map)
                      : pattern);
 
   kwsinit (&kwset);
 
-  char const *beg = pat;
+  p = pat;
   do
     {
-      char const *lim;
-      char const *end;
-      for (lim = beg;; ++lim)
+      size_t len;
+      sep = memchr (p, '\n', total);
+      if (sep)
         {
-          end = lim;
-          if (lim >= pat + psize)
-            break;
-         if (*lim == '\n')
-           {
-             lim++;
-             break;
-           }
+          len = sep - p;
+          sep++;
+          total -= (len + 1);
 #if HAVE_DOS_FILE_CONTENTS
-         if (*lim == '\r' && lim + 1 < pat + psize && lim[1] == '\n')
-           {
-             lim += 2;
-             break;
-           }
+         if (sep[-1] == '\r')
+           --len;
 #endif
         }
+      else
+        {
+          len = total;
+          total = 0;
+        }
 
-      kwsincr (kwset, beg, end - beg);
-      beg = lim;
-    }
-  while (beg < pat + psize);
+      kwsincr (kwset, p, len);
+
+      p = sep;
+    } while (sep && total != 0);
+
+  if (sep)
+    kwsincr (kwset, "", 0);
 
   kwsprep (kwset);
 }
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 219e96a..49d6cba 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -54,6 +54,7 @@ TESTS =						\
   dfa-heap-overrun				\
   dfaexec-multibyte				\
   empty						\
+  empty-line					\
   epipe						\
   equiv-classes					\
   ere						\
diff --git a/tests/empty-line b/tests/empty-line
new file mode 100755
index 0000000..aeaa6ca
--- /dev/null
+++ b/tests/empty-line
@@ -0,0 +1,17 @@
+#! /bin/sh
+# This would fail for grep-2.18
+
+. "${srcdir=.}/init.sh"; path_prepend_ ../src
+
+fail=0
+printf 'abc\n' >in || framework_failure_
+
+printf 'foo\n\n' >pat || framework_failure_
+grep -F -f pat in >out || fail=1
+compare in out || fail=1
+
+printf '\(\)\\1foo\n\n' >pat || framework_failure_
+grep -f pat in >out || fail=1
+compare in out || fail=1
+
+Exit $fail
-- 
1.9.2