3 files changed, 107 insertions, 28 deletions

diff --git a/shell/hush.c b/shell/hush.c
index c67aebdd7..c5a8ea617 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -221,7 +221,8 @@
 //config:       default y
 //config:       depends on HUSH
 //config:       help
-//config:         This instructs hush to print commands before execution. Adds ~300 bytes.
+//config:         This instructs hush to print commands before execution.
+//config:         Adds ~300 bytes.
 //config:
 
 //usage:#define hush_trivial_usage NOUSAGE_STR
@@ -664,7 +665,7 @@ struct globals {
         smallint n_mode;
 #if ENABLE_HUSH_MODE_X
         smallint x_mode;
-# define G_x_mode G.x_mode
+# define G_x_mode (G.x_mode)
 #else
 # define G_x_mode 0
 #endif
@@ -688,6 +689,7 @@ struct globals {
         const char *cwd;
         struct variable *top_var; /* = &G.shell_ver (set in main()) */
         struct variable shell_ver;
+        char **expanded_assignments;
 #if ENABLE_HUSH_FUNCTIONS
         struct function *top_func;
 # if ENABLE_HUSH_LOCAL
@@ -1459,9 +1461,23 @@ static struct variable *get_local_var(const char *name)
 
 static const char* FAST_FUNC get_local_var_value(const char *name)
 {
-        struct variable **pp = get_ptr_to_local_var(name);
-        if (pp)
-                return strchr((*pp)->varstr, '=') + 1;
+        struct variable **vpp;
+
+        if (G.expanded_assignments) {
+                char **cpp = G.expanded_assignments;
+                int len = strlen(name);
+                while (*cpp) {
+                        char *cp = *cpp;
+                        if (strncmp(cp, name, len) == 0 && cp[len] == '=')
+                                return cp + len + 1;
+                        cpp++;
+                }
+        }
+
+        vpp = get_ptr_to_local_var(name);
+        if (vpp)
+                return strchr((*vpp)->varstr, '=') + 1;
+
         if (strcmp(name, "PPID") == 0)
                 return utoa(G.root_ppid);
         // bash compat: UID? EUID?
@@ -3090,11 +3106,14 @@ static char* expand_strvec_to_string(char **argv)
 static char **expand_assignments(char **argv, int count)
 {
         int i;
-        char **p = NULL;
+        char **p;
+
+        G.expanded_assignments = p = NULL;
         /* Expand assignments into one string each */
         for (i = 0; i < count; i++) {
-                p = add_string_to_strings(p, expand_string_to_string(argv[i]));
+                G.expanded_assignments = p = add_string_to_strings(p, expand_string_to_string(argv[i]));
         }
+        G.expanded_assignments = NULL;
         return p;
 }
 
@@ -4316,6 +4335,27 @@ static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
  * backgrounded: cmd &     { list } &
  * subshell:     ( list ) [&]
  */
+#if !ENABLE_HUSH_MODE_X
+#define redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel, char argv_expanded) \
+        redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel)
+#endif
+static int redirect_and_varexp_helper(char ***new_env_p, struct variable **old_vars_p, struct command *command, int squirrel[3], char **argv_expanded)
+{
+        /* setup_redirects acts on file descriptors, not FILEs.
+         * This is perfect for work that comes after exec().
+         * Is it really safe for inline use?  Experimentally,
+         * things seem to work. */
+        int rcode = setup_redirects(command, squirrel);
+        if (rcode == 0) {
+                char **new_env = expand_assignments(command->argv, command->assignment_cnt);
+                *new_env_p = new_env;
+                dump_cmd_in_x_mode(new_env);
+                dump_cmd_in_x_mode(argv_expanded);
+                if (old_vars_p)
+                        *old_vars_p = set_vars_and_save_old(new_env);
+        }
+        return rcode;
+}
 static NOINLINE int run_pipe(struct pipe *pi)
 {
         static const char *const null_ptr = NULL;
@@ -4325,7 +4365,6 @@ static NOINLINE int run_pipe(struct pipe *pi)
         struct command *command;
         char **argv_expanded;
         char **argv;
-        char *p;
         /* it is not always needed, but we aim to smaller code */
         int squirrel[] = { -1, -1, -1 };
         int rcode;
@@ -4402,19 +4441,45 @@ static NOINLINE int run_pipe(struct pipe *pi)
                 if (argv[command->assignment_cnt] == NULL) {
                         /* Assignments, but no command */
                         /* Ensure redirects take effect (that is, create files).
-                         * Try "a=t >file": */
+                         * Try "a=t >file" */
+#if 0 /* A few cases in testsuite fail with this code. FIXME */
+                        rcode = redirect_and_varexp_helper(&new_env, /*old_vars:*/ NULL, command, squirrel, /*argv_expanded:*/ NULL);
+                        /* Set shell variables */
+                        if (new_env) {
+                                argv = new_env;
+                                while (*argv) {
+                                        set_local_var(*argv, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
+                                        /* Do we need to flag set_local_var() errors?
+                                         * "assignment to readonly var" and "putenv error"
+                                         */
+                                        argv++;
+                                }
+                        }
+                        /* Redirect error sets $? to 1. Otherwise,
+                         * if evaluating assignment value set $?, retain it.
+                         * Try "false; q=`exit 2`; echo $?" - should print 2: */
+                        if (rcode == 0)
+                                rcode = G.last_exitcode;
+                        /* Exit, _skipping_ variable restoring code: */
+                        goto clean_up_and_ret0;
+
+#else /* Older, bigger, but more correct code */
+
                         rcode = setup_redirects(command, squirrel);
                         restore_redirects(squirrel);
                         /* Set shell variables */
                         if (G_x_mode)
                                 bb_putchar_stderr('+');
                         while (*argv) {
-                                p = expand_string_to_string(*argv);
+                                char *p = expand_string_to_string(*argv);
                                 if (G_x_mode)
                                         fprintf(stderr, " %s", p);
                                 debug_printf_exec("set shell var:'%s'->'%s'\n",
                                                 *argv, p);
                                 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
+                                /* Do we need to flag set_local_var() errors?
+                                 * "assignment to readonly var" and "putenv error"
+                                 */
                                 argv++;
                         }
                         if (G_x_mode)
@@ -4424,13 +4489,11 @@ static NOINLINE int run_pipe(struct pipe *pi)
                          * Try "false; q=`exit 2`; echo $?" - should print 2: */
                         if (rcode == 0)
                                 rcode = G.last_exitcode;
-                        /* Do we need to flag set_local_var() errors?
-                         * "assignment to readonly var" and "putenv error"
-                         */
                         IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
                         debug_leave();
                         debug_printf_exec("run_pipe: return %d\n", rcode);
                         return rcode;
+#endif
                 }
 
                 /* Expand the rest into (possibly) many strings each */
@@ -4471,16 +4534,8 @@ static NOINLINE int run_pipe(struct pipe *pi)
                                         goto clean_up_and_ret1;
                                 }
                         }
-                        /* setup_redirects acts on file descriptors, not FILEs.
-                         * This is perfect for work that comes after exec().
-                         * Is it really safe for inline use?  Experimentally,
-                         * things seem to work. */
-                        rcode = setup_redirects(command, squirrel);
+                        rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
                         if (rcode == 0) {
-                                new_env = expand_assignments(argv, command->assignment_cnt);
-                                dump_cmd_in_x_mode(new_env);
-                                dump_cmd_in_x_mode(argv_expanded);
-                                old_vars = set_vars_and_save_old(new_env);
                                 if (!funcp) {
                                         debug_printf_exec(": builtin '%s' '%s'...\n",
                                                 x->b_cmd, argv_expanded[1]);
@@ -4504,9 +4559,10 @@ static NOINLINE int run_pipe(struct pipe *pi)
 #endif
                         }
  clean_up_and_ret:
-                        restore_redirects(squirrel);
                         unset_vars(new_env);
                         add_vars(old_vars);
+/* clean_up_and_ret0: */
+                        restore_redirects(squirrel);
  clean_up_and_ret1:
                         free(argv_expanded);
                         IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
@@ -4518,12 +4574,8 @@ static NOINLINE int run_pipe(struct pipe *pi)
                 if (ENABLE_FEATURE_SH_STANDALONE) {
                         int n = find_applet_by_name(argv_expanded[0]);
                         if (n >= 0 && APPLET_IS_NOFORK(n)) {
-                                rcode = setup_redirects(command, squirrel);
+                                rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
                                 if (rcode == 0) {
-                                        new_env = expand_assignments(argv, command->assignment_cnt);
-                                        dump_cmd_in_x_mode(new_env);
-                                        dump_cmd_in_x_mode(argv_expanded);
-                                        old_vars = set_vars_and_save_old(new_env);
                                         debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
                                                 argv_expanded[0], argv_expanded[1]);
                                         rcode = run_nofork_applet(n, argv_expanded);
diff --git a/shell/hush_test/hush-vars/var_serial.right b/shell/hush_test/hush-vars/var_serial.right
new file mode 100644
index 000000000..42aa33057
--- /dev/null
+++ b/shell/hush_test/hush-vars/var_serial.right
@@ -0,0 +1,5 @@
+Assignments only: c=a
+Assignments and a command: c=a
+Assignments and a builtin: c=a
+Assignments and a function: c=a
+Done
diff --git a/shell/hush_test/hush-vars/var_serial.tests b/shell/hush_test/hush-vars/var_serial.tests
new file mode 100755
index 000000000..6b4a4cdf7
--- /dev/null
+++ b/shell/hush_test/hush-vars/var_serial.tests
@@ -0,0 +1,22 @@
+a=a
+
+b=b
+c=c
+# Second assignment depends on the first:
+b=$a c=$b
+echo Assignments only: c=$c
+
+b=b
+c=c
+b=$a c=$b "$THIS_SH" -c 'echo Assignments and a command: c=$c'
+
+b=b
+c=c
+b=$a c=$b eval 'echo Assignments and a builtin: c=$c'
+
+b=b
+c=c
+f() { echo Assignments and a function: c=$c; }
+b=$a c=$b f
+
+echo Done