ash: fix error during recursive processing of here document

Save the value of the checkkwd flag to prevent it being clobbered
during recursion.

Based on commit ec2c84d from git://git.kernel.org/pub/scm/utils/dash/dash.git
by Herbert Xu.

function                                             old     new   delta
readtoken                                            190     203     +13
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/0 up/down: 13/0)               Total: 13 bytes

Signed-off-by: Ron Yorston <rmy@pobox.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

3 files changed, 13 insertions, 2 deletions

diff --git a/shell/ash.c b/shell/ash.c
index 0d7cac0b5..384c7b9e4 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -11899,6 +11899,7 @@ static int
 readtoken(void)
 {
         int t;
+        int kwd = checkkwd;
 #if DEBUG
         smallint alreadyseen = tokpushback;
 #endif
@@ -11912,7 +11913,7 @@ readtoken(void)
         /*
          * eat newlines
          */
-        if (checkkwd & CHKNL) {
+        if (kwd & CHKNL) {
                 while (t == TNL) {
                         parseheredoc();
                         t = xxreadtoken();
@@ -11926,7 +11927,7 @@ readtoken(void)
         /*
          * check for keywords
          */
-        if (checkkwd & CHKKWD) {
+        if (kwd & CHKKWD) {
                 const char *const *pp;
 
                 pp = findkwd(wordtext);
diff --git a/shell/ash_test/ash-heredoc/heredoc3.right b/shell/ash_test/ash-heredoc/heredoc3.right
new file mode 100644
index 000000000..ce0136250
--- /dev/null
+++ b/shell/ash_test/ash-heredoc/heredoc3.right
@@ -0,0 +1 @@
+hello
diff --git a/shell/ash_test/ash-heredoc/heredoc3.tests b/shell/ash_test/ash-heredoc/heredoc3.tests
new file mode 100755
index 000000000..96c227cc1
--- /dev/null
+++ b/shell/ash_test/ash-heredoc/heredoc3.tests
@@ -0,0 +1,9 @@
+echo hello >greeting
+cat <<EOF &&
+$(cat greeting)
+EOF
+{
+        echo $?
+        cat greeting
+} >/dev/null
+rm greeting