From 3fe4f986a055d0bc942dcda0c2fea3ef68e341d7 Mon Sep 17 00:00:00 2001
From: Denis Vlasenko <vda.linux@googlemail.com>
Date: Mon, 9 Jun 2008 16:02:39 +0000
Subject: [PATCH] less: fix a case when regexp matches "" hush: remove wrong
 comment, expand another one

---
 miscutils/less.c | 23 +++++++++++++----------
 shell/hush.c     |  5 ++++-
 2 files changed, 17 insertions(+), 11 deletions(-)

diff --git a/miscutils/less.c b/miscutils/less.c
index 0529b2047..ecdb9ae60 100644
--- a/miscutils/less.c
+++ b/miscutils/less.c
@@ -172,16 +172,6 @@ static void set_tty_cooked(void)
 	tcsetattr(kbd_fd, TCSANOW, &term_orig);
 }
 
-/* Exit the program gracefully */
-static void less_exit(int code)
-{
-	bb_putchar('\n');
-	set_tty_cooked();
-	if (code < 0)
-		kill_myself_with_sig(- code); /* does not return */
-	exit(code);
-}
-
 /* Move the cursor to a position (x,y), where (0,0) is the
    top-left corner of the console */
 static void move_cursor(int line, int row)
@@ -205,6 +195,16 @@ static void print_statusline(const char *str)
 	printf(HIGHLIGHT"%.*s"NORMAL, width - 1, str);
 }
 
+/* Exit the program gracefully */
+static void less_exit(int code)
+{
+	set_tty_cooked();
+	clear_line();
+	if (code < 0)
+		kill_myself_with_sig(- code); /* does not return */
+	exit(code);
+}
+
 #if ENABLE_FEATURE_LESS_REGEXP
 static void fill_match_lines(unsigned pos);
 #else
@@ -538,6 +538,9 @@ static void print_found(const char *line)
  start:
 		/* Most of the time doesn't find the regex, optimize for that */
 		match_status = regexec(&pattern, line, 1, &match_structs, eflags);
+		/* if even "" matches, treat it as "not a match" */
+		if (match_structs.rm_so >= match_structs.rm_eo)
+			match_status = 1;
 	}
 
 	if (!growline) {
diff --git a/shell/hush.c b/shell/hush.c
index 9e574c90c..b80468f58 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -3218,7 +3218,6 @@ static int redirect_opt_num(o_string *o)
 }
 
 #if ENABLE_HUSH_TICK
-/* NB: currently disabled on NOMMU */
 static FILE *generate_stream_from_list(struct pipe *head)
 {
 	FILE *pf;
@@ -3229,6 +3228,10 @@ static FILE *generate_stream_from_list(struct pipe *head)
 /* By using vfork here, we suspend parent till child exits or execs.
  * If child will not do it before it fills the pipe, it can block forever
  * in write(STDOUT_FILENO), and parent (shell) will be also stuck.
+ * Try this script:
+ * yes "0123456789012345678901234567890" | dd bs=32 count=64k >TESTFILE
+ * huge=`cat TESTFILE` # will block here forever
+ * echo OK
  */
 	pid = BB_MMU ? fork() : vfork();
 	if (pid < 0)
-- 
2.25.1