ash: fix interactive "command eval STRING" exiting on errors.

This bug is also present in current dash

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

3 files changed, 33 insertions, 1 deletions

diff --git a/shell/ash.c b/shell/ash.c
index 1ef02b8be..fe112453c 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -2180,6 +2180,7 @@ setvareq(char *s, int flags)
                         if (flags & VNOSAVE)
                                 free(s);
                         n = vp->var_text;
+                        exitstatus = 1;
                         ash_msg_and_raise_error("%.*s: is read only", strchrnul(n, '=') - n, n);
                 }
 
@@ -9599,7 +9600,7 @@ evalcommand(union node *cmd, int flags)
                 if (evalbltin(cmdentry.u.cmd, argc, argv, flags)) {
                         if (exception_type == EXERROR && spclbltin <= 0) {
                                 FORCE_INT_ON;
-                                break;
+                                goto readstatus;
                         }
  raise:
                         longjmp(exception_handler->loc, 1);
@@ -12280,6 +12281,10 @@ expandstr(const char *ps)
 static int
 evalstring(char *s, int flags)
 {
+        struct jmploc *volatile savehandler = exception_handler;
+        struct jmploc jmploc;
+        int ex;
+
         union node *n;
         struct stackmark smark;
         int status;
@@ -12289,6 +12294,19 @@ evalstring(char *s, int flags)
         setstackmark(&smark);
 
         status = 0;
+        /* On exception inside execution loop, we must popfile().
+         * Try interactively:
+         *      readonly a=a
+         *      command eval "a=b"  # throws "is read only" error
+         * "command BLTIN" is not supposed to abort (even in non-interactive use).
+         * But if we skip popfile(), we hit EOF in eval's string, and exit.
+         */
+        savehandler = exception_handler;
+        exception_handler = &jmploc;
+        ex = setjmp(jmploc.loc);
+        if (ex)
+                goto out;
+
         while ((n = parsecmd(0)) != NODE_EOF) {
                 int i;
 
@@ -12299,10 +12317,15 @@ evalstring(char *s, int flags)
                 if (evalskip)
                         break;
         }
+ out:
         popstackmark(&smark);
         popfile();
         stunalloc(s);
 
+        exception_handler = savehandler;
+        if (ex)
+                longjmp(exception_handler->loc, ex);
+
         return status;
 }
 
diff --git a/shell/ash_test/ash-vars/readonly1.right b/shell/ash_test/ash-vars/readonly1.right
new file mode 100644
index 000000000..2b363e325
--- /dev/null
+++ b/shell/ash_test/ash-vars/readonly1.right
@@ -0,0 +1,2 @@
+One:1
+One:1
diff --git a/shell/ash_test/ash-vars/readonly1.tests b/shell/ash_test/ash-vars/readonly1.tests
new file mode 100755
index 000000000..81b461f5f
--- /dev/null
+++ b/shell/ash_test/ash-vars/readonly1.tests
@@ -0,0 +1,7 @@
+readonly bla=123
+# Bare "eval bla=123" should abort ("eval" is a special builtin):
+(eval bla=123 2>/dev/null; echo BUG)
+echo One:$?
+# "command BLTIN" disables "special-ness", should not abort:
+command eval bla=123 2>/dev/null
+echo One:$?