hush: more rodust detection of unterminated strings etc;

 fix a case where we forget to copy `cmd` text;
 optimize nommu heredoc helper by not passing environment to it;
 add several tests

function                                             old     new   delta
add_till_closing_paren                               256     308     +52
parse_stream                                        2337    2378     +41
add_till_backquote                                    82     111     +29
re_execute_shell                                     269     284     +15
handle_dollar                                        802     812     +10
parse_stream_dquoted                                 316     320      +4
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 6/0 up/down: 151/0)             Total: 151 bytes

7 files changed, 177 insertions, 31 deletions

diff --git a/shell/hush.c b/shell/hush.c
index 4641dca11..9920e98c6 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -2241,7 +2241,10 @@ static void re_execute_shell(const char *s, int is_heredoc)
 
 	debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
 	sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
-	execv(bb_busybox_exec_path, G.argv_from_re_execing);
+	execve(bb_busybox_exec_path,
+		G.argv_from_re_execing,
+		(is_heredoc ? pp /* points to NULL ptr */ : environ)
+		);
 	/* Fallback. Useful for init=/bin/hush usage etc */
 	if (G.argv0_for_re_execing[0] == '/')
 		execv(G.argv0_for_re_execing, G.argv_from_re_execing);
@@ -4402,35 +4405,40 @@ static int parse_group(o_string *dest, struct parse_context *ctx,
 
 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
 /* Subroutines for copying $(...) and `...` things */
-static void add_till_backquote(o_string *dest, struct in_str *input);
+static int add_till_backquote(o_string *dest, struct in_str *input);
 /* '...' */
-static void add_till_single_quote(o_string *dest, struct in_str *input)
+static int add_till_single_quote(o_string *dest, struct in_str *input)
 {
 	while (1) {
 		int ch = i_getch(input);
-		if (ch == EOF)
-			break;
+		if (ch == EOF) {
+			syntax("unterminated '");
+			return 1;
+		}
 		if (ch == '\'')
-			break;
+			return 0;
 		o_addchr(dest, ch);
 	}
 }
 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
-static void add_till_double_quote(o_string *dest, struct in_str *input)
+static int add_till_double_quote(o_string *dest, struct in_str *input)
 {
 	while (1) {
 		int ch = i_getch(input);
+		if (ch == EOF) {
+			syntax("unterminated \"");
+			return 1;
+		}
 		if (ch == '"')
-			break;
+			return 0;
 		if (ch == '\\') {  /* \x. Copy both chars. */
 			o_addchr(dest, ch);
 			ch = i_getch(input);
 		}
-		if (ch == EOF)
-			break;
 		o_addchr(dest, ch);
 		if (ch == '`') {
-			add_till_backquote(dest, input);
+			if (add_till_backquote(dest, input))
+				return 1;
 			o_addchr(dest, ch);
 			continue;
 		}
@@ -4451,20 +4459,27 @@ static void add_till_double_quote(o_string *dest, struct in_str *input)
  * Example                               Output
  * echo `echo '\'TEST\`echo ZZ\`BEST`    \TESTZZBEST
  */
-static void add_till_backquote(o_string *dest, struct in_str *input)
+static int add_till_backquote(o_string *dest, struct in_str *input)
 {
 	while (1) {
 		int ch = i_getch(input);
+		if (ch == EOF) {
+			syntax("unterminated `");
+			return 1;
+		}
 		if (ch == '`')
-			break;
-		if (ch == '\\') {  /* \x. Copy both chars unless it is \` */
+			return 0;
+		if (ch == '\\') {
+			/* \x. Copy both chars unless it is \` */
 			int ch2 = i_getch(input);
+			if (ch2 == EOF) {
+				syntax("unterminated `");
+				return 1;
+			}
 			if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
 				o_addchr(dest, ch);
 			ch = ch2;
 		}
-		if (ch == EOF)
-			break;
 		o_addchr(dest, ch);
 	}
 }
@@ -4480,13 +4495,15 @@ static void add_till_backquote(o_string *dest, struct in_str *input)
  * echo $(echo 'TEST)' BEST)            TEST) BEST
  * echo $(echo \(\(TEST\) BEST)         ((TEST) BEST
  */
-static void add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl)
+static int add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl)
 {
 	int count = 0;
 	while (1) {
 		int ch = i_getch(input);
-		if (ch == EOF)
-			break;
+		if (ch == EOF) {
+			syntax("unterminated )");
+			return 1;
+		}
 		if (ch == '(')
 			count++;
 		if (ch == ')') {
@@ -4501,23 +4518,29 @@ static void add_till_closing_paren(o_string *dest, struct in_str *input, bool db
 		}
 		o_addchr(dest, ch);
 		if (ch == '\'') {
-			add_till_single_quote(dest, input);
+			if (add_till_single_quote(dest, input))
+				return 1;
 			o_addchr(dest, ch);
 			continue;
 		}
 		if (ch == '"') {
-			add_till_double_quote(dest, input);
+			if (add_till_double_quote(dest, input))
+				return 1;
 			o_addchr(dest, ch);
 			continue;
 		}
-		if (ch == '\\') { /* \x. Copy verbatim. Important for  \(, \) */
+		if (ch == '\\') {
+			/* \x. Copy verbatim. Important for  \(, \) */
 			ch = i_getch(input);
-			if (ch == EOF)
-				break;
+			if (ch == EOF) {
+				syntax("unterminated )");
+				return 1;
+			}
 			o_addchr(dest, ch);
 			continue;
 		}
 	}
+	return 0;
 }
 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
 
@@ -4658,7 +4681,8 @@ static int handle_dollar(o_string *as_string,
 #  if !BB_MMU
 			pos = dest->length;
 #  endif
-			add_till_closing_paren(dest, input, true);
+			if (add_till_closing_paren(dest, input, true))
+				return 1;
 #  if !BB_MMU
 			if (as_string) {
 				o_addstr(as_string, dest->data + pos);
@@ -4671,20 +4695,19 @@ static int handle_dollar(o_string *as_string,
 		}
 # endif
 # if ENABLE_HUSH_TICK
-		//int pos = dest->length;
 		o_addchr(dest, SPECIAL_VAR_SYMBOL);
 		o_addchr(dest, quote_mask | '`');
 #  if !BB_MMU
 		pos = dest->length;
 #  endif
-		add_till_closing_paren(dest, input, false);
+		if (add_till_closing_paren(dest, input, false))
+			return 1;
 #  if !BB_MMU
 		if (as_string) {
 			o_addstr(as_string, dest->data + pos);
 			o_addchr(as_string, '`');
 		}
 #  endif
-		//debug_printf_subst("SUBST RES2 '%s'\n", dest->data + pos);
 		o_addchr(dest, SPECIAL_VAR_SYMBOL);
 # endif
 		break;
@@ -4778,7 +4801,8 @@ static int parse_stream_dquoted(o_string *as_string,
 		//int pos = dest->length;
 		o_addchr(dest, SPECIAL_VAR_SYMBOL);
 		o_addchr(dest, 0x80 | '`');
-		add_till_backquote(dest, input);
+		if (add_till_backquote(dest, input))
+			return 1;
 		o_addchr(dest, SPECIAL_VAR_SYMBOL);
 		//debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
 		goto again;
@@ -5043,10 +5067,20 @@ static struct pipe *parse_stream(char **pstring,
 			break;
 #if ENABLE_HUSH_TICK
 		case '`': {
-			//int pos = dest.length;
+#if !BB_MMU
+			int pos;
+#endif
 			o_addchr(&dest, SPECIAL_VAR_SYMBOL);
 			o_addchr(&dest, '`');
-			add_till_backquote(&dest, input);
+#if !BB_MMU
+			pos = dest.length;
+#endif
+			if (add_till_backquote(&dest, input))
+				goto parse_error;
+#if !BB_MMU
+			o_addstr(&ctx.as_string, dest.data + pos);
+			o_addchr(&ctx.as_string, '`');
+#endif
 			o_addchr(&dest, SPECIAL_VAR_SYMBOL);
 			//debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
 			break;
diff --git a/shell/hush_test/hush-misc/heredoc_huge.right b/shell/hush_test/hush-misc/heredoc_huge.right
new file mode 100644
index 000000000..11740f674
--- /dev/null
+++ b/shell/hush_test/hush-misc/heredoc_huge.right
@@ -0,0 +1,3 @@
+546ed3f5c81c780d3ab86ada14824237  -
+546ed3f5c81c780d3ab86ada14824237  -
+End
diff --git a/shell/hush_test/hush-misc/heredoc_huge.tests b/shell/hush_test/hush-misc/heredoc_huge.tests
new file mode 100755
index 000000000..c2ec2817b
--- /dev/null
+++ b/shell/hush_test/hush-misc/heredoc_huge.tests
@@ -0,0 +1,9 @@
+# This creates 120k heredoc
+echo 'cat <<HERE | md5sum' >"$0.tmp"
+yes "123456789 123456789 123456789 123456789" | head -3000 >>"$0.tmp"
+echo 'HERE' >>"$0.tmp"
+
+yes "123456789 123456789 123456789 123456789" | head -3000 | md5sum
+. "$0.tmp"
+rm "$0.tmp"
+echo End
diff --git a/shell/hush_test/hush-psubst/tick_huge.right b/shell/hush_test/hush-psubst/tick_huge.right
new file mode 100644
index 000000000..11740f674
--- /dev/null
+++ b/shell/hush_test/hush-psubst/tick_huge.right
@@ -0,0 +1,3 @@
+546ed3f5c81c780d3ab86ada14824237  -
+546ed3f5c81c780d3ab86ada14824237  -
+End
diff --git a/shell/hush_test/hush-psubst/tick_huge.tests b/shell/hush_test/hush-psubst/tick_huge.tests
new file mode 100755
index 000000000..acce92fb2
--- /dev/null
+++ b/shell/hush_test/hush-psubst/tick_huge.tests
@@ -0,0 +1,7 @@
+# This creates 120k file
+yes "123456789 123456789 123456789 123456789" | head -3000 >>"$0.tmp"
+
+echo "`cat $0.tmp`" | md5sum
+rm "$0.tmp"
+yes "123456789 123456789 123456789 123456789" | head -3000 | md5sum
+echo End
diff --git a/shell/hush_test/hush-z_slow/leak_all2.right b/shell/hush_test/hush-z_slow/leak_all2.right
new file mode 100644
index 000000000..c6f0334f3
--- /dev/null
+++ b/shell/hush_test/hush-z_slow/leak_all2.right
@@ -0,0 +1,3 @@
+Warm up
+Measuring memory leak...
+Ok
diff --git a/shell/hush_test/hush-z_slow/leak_all2.tests b/shell/hush_test/hush-z_slow/leak_all2.tests
new file mode 100755
index 000000000..8fb1ca9b4
--- /dev/null
+++ b/shell/hush_test/hush-z_slow/leak_all2.tests
@@ -0,0 +1,87 @@
+# "Check many leaks" test #2
+# Cramming all kinds of weird commands in here.
+# As you find leaks, please create separate, small test
+# for each leak.
+# Narrowing down the leak using this large test may be difficult.
+# It is intended to be a blanket "is everything ok?" test
+
+echo "Warm up"
+local_var="local val"
+export dev_null="/dev/null"
+>$dev_null
+echo hi1 $local_var `echo ho` >>/dev/null
+echo hi2 $local_var </dev/null | echo 2>&- | cat 1<>/dev/null
+{ echo hi4 $local_var `echo ho` 1<>/dev/null; }
+( echo hi4 $local_var `echo ho` 1<>/dev/null )
+if echo $local_var; false
+    then echo not run
+    elif false <$dev_null
+    then none
+    else cat 0<>$dev_null 1<>"$dev_null"
+fi >>/dev/null
+{
+    if echo $local_var; then cat <<HERE
+Hi cat
+HERE
+    fi >>/dev/null
+} 1<>/dev/null
+while { echo $dev_null >>$dev_null; }; do cat <"$dev_null"; break; done
+( until { echo $dev_null >>$dev_null | false; }; do cat <"$dev_null"; break; done ) <$dev_null
+
+memleak
+
+echo "Measuring memory leak..."
+# Please copy the entire block from above verbatim
+local_var="local val"
+export dev_null="/dev/null"
+>$dev_null
+echo hi1 $local_var `echo ho` >>/dev/null
+echo hi2 $local_var </dev/null | echo 2>&- | cat 1<>/dev/null
+{ echo hi4 $local_var `echo ho` 1<>/dev/null; }
+( echo hi4 $local_var `echo ho` 1<>/dev/null )
+if echo $local_var; false
+    then echo not run
+    elif false <$dev_null
+    then none
+    else cat 0<>$dev_null 1<>"$dev_null"
+fi >>/dev/null
+{
+    if echo $local_var; then cat <<HERE
+Hi cat
+HERE
+    fi >>/dev/null
+} 1<>/dev/null
+while { echo $dev_null >>$dev_null; }; do cat <"$dev_null"; break; done
+( until { echo $dev_null >>$dev_null | false; }; do cat <"$dev_null"; break; done ) <$dev_null
+
+# And same again
+
+local_var="local val"
+export dev_null="/dev/null"
+>$dev_null
+echo hi1 $local_var `echo ho` >>/dev/null
+echo hi2 $local_var </dev/null | echo 2>&- | cat 1<>/dev/null
+{ echo hi4 $local_var `echo ho` 1<>/dev/null; }
+( echo hi4 $local_var `echo ho` 1<>/dev/null )
+if echo $local_var; false
+    then echo not run
+    elif false <$dev_null
+    then none
+    else cat 0<>$dev_null 1<>"$dev_null"
+fi >>/dev/null
+{
+    if echo $local_var; then cat <<HERE
+Hi cat
+HERE
+    fi >>/dev/null
+} 1<>/dev/null
+while { echo $dev_null >>$dev_null; }; do cat <"$dev_null"; break; done
+( until { echo $dev_null >>$dev_null | false; }; do cat <"$dev_null"; break; done ) <$dev_null
+
+memleak
+kb=$?
+if test $kb -le 4; then
+    echo Ok #$kb
+else
+    echo "Bad: $kb kb (or more) leaked"
+fi