ash: parser: Save and restore heredoclist in expandstr

Upstream commit:

    Date: Sun, 17 May 2020 23:36:25 +1000
    parser: Save and restore heredoclist in expandstr

    On Sun, May 17, 2020 at 01:19:28PM +0100, Harald van Dijk wrote:
    > This still does not restore the state completely. It does not clean up any
    > pending heredocs. I see:
    >
    >   $ PS1='$(<<EOF "'
    >   src/dash: 1: Syntax error: Unterminated quoted string
    >   $(<<EOF ":
    >   >
    >
    > That is, after entering the ':' command, the shell is still trying to read
    > the heredoc from the prompt.

    This patch saves and restores the heredoclist in expandstr.

    It also removes a bunch of unnecessary volatiles as those variables
    are only referenced in case of a longjmp other than one started by
    a signal like SIGINT.

function                                             old     new   delta
expandstr                                            268     255     -13

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 11 insertions, 8 deletions

diff --git a/shell/ash.c b/shell/ash.c
index 5a18ff1a1..cf62fdf75 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -13359,23 +13359,26 @@ parseheredoc(void)
 static const char *
 expandstr(const char *ps, int syntax_type)
 {
-        union node n;
+        struct parsefile *file_stop;
+        struct jmploc *volatile savehandler;
+        struct heredoc *saveheredoclist;
+        const char *result;
         int saveprompt;
-        struct parsefile *file_stop = g_parsefile;
-        volatile int saveint;
-        struct jmploc *volatile savehandler = exception_handler;
         struct jmploc jmploc;
-        const char *volatile result;
+        union node n;
         int err;
 
+        file_stop = g_parsefile;
+
         /* XXX Fix (char *) cast. */
         setinputstring((char *)ps);
 
+        saveheredoclist = heredoclist;
+        heredoclist = NULL;
         saveprompt = doprompt;
         doprompt = 0;
         result = ps;
-
-        SAVE_INT(saveint);
+        savehandler = exception_handler;
         err = setjmp(jmploc.loc);
         if (err)
                 goto out;
@@ -13402,11 +13405,11 @@ out:
         exception_handler = savehandler;
         if (err && exception_type != EXERROR)
                 longjmp(exception_handler->loc, 1);
-        RESTORE_INT(saveint);
 
         doprompt = saveprompt;
         /* Try: PS1='`xxx(`' */
         unwindfiles(file_stop);
+        heredoclist = saveheredoclist;
 
         return result;
 }