hush: fix readonly2.tests failure

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

3 files changed, 13 insertions, 0 deletions

diff --git a/shell/hush.c b/shell/hush.c
index 55e581e16..f6da826d3 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -2287,7 +2287,18 @@ static struct variable *set_vars_and_save_old(char **strings)
                         if (var_pp) {
                                 var_p = *var_pp;
                                 if (var_p->flg_read_only) {
+                                        char **p;
                                         bb_error_msg("%s: readonly variable", *s);
+                                        /*
+                                         * "VAR=V BLTIN" unsets VARs after BLTIN completes.
+                                         * If VAR is readonly, leaving it in the list
+                                         * after asssignment error (msg above)
+                                         * causes doubled error message later, on unset.
+                                         */
+                                        debug_printf_env("removing/freeing '%s' element\n", *s);
+                                        free(*s);
+                                        p = s;
+                                        do { *p = p[1]; p++; } while (*p);
                                         goto next;
                                 }
                                 /* Remove variable from global linked list */
diff --git a/shell/hush_test/hush-vars/readonly2.right b/shell/hush_test/hush-vars/readonly2.right
index 5b02ddfe8..38551d4ad 100644
--- a/shell/hush_test/hush-vars/readonly2.right
+++ b/shell/hush_test/hush-vars/readonly2.right
@@ -1,4 +1,5 @@
 hush: a=Z: readonly variable
 Visible:42
+
 hush: a=Z: readonly variable
 Visible:42
diff --git a/shell/hush_test/hush-vars/readonly2.tests b/shell/hush_test/hush-vars/readonly2.tests
index d9d178edd..b758d9602 100755
--- a/shell/hush_test/hush-vars/readonly2.tests
+++ b/shell/hush_test/hush-vars/readonly2.tests
@@ -3,4 +3,5 @@ readonly a=A
 
 # external commands and builtins should behave the same:
 (exit 42); a=Z echo "Visible:$?"
+echo
 (exit 42); a=Z env echo "Visible:$?"