hush: fix break'ing out of {} and () groups; with testcase

function                                             old     new   delta
builtin_break                                         93     129     +36
builtin_continue                                      21      47     +26
run_list                                            1973    1976      +3

3 files changed, 43 insertions, 13 deletions

diff --git a/shell/hush.c b/shell/hush.c
index 8ffc6121a..eb70c9d9f 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -446,6 +446,7 @@ struct globals {
         int global_argc;
 #if ENABLE_HUSH_LOOPS
         unsigned depth_break_continue;
+        unsigned depth_of_loop;
 #endif
         pid_t last_bg_pid;
         const char *ifs;
@@ -496,6 +497,7 @@ enum { run_list_level = 0 };
 #define ifs              (G.ifs             )
 #define flag_break_continue  (G.flag_break_continue )
 #define depth_break_continue (G.depth_break_continue)
+#define depth_of_loop    (G.depth_of_loop   )
 #define fake_mode        (G.fake_mode       )
 #define cwd              (G.cwd             )
 #define last_bg_pid      (G.last_bg_pid     )
@@ -2153,13 +2155,14 @@ static int run_list(struct pipe *pi)
                 if (rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR) {
                         /* start of a loop: remember where loop starts */
                         loop_top = pi;
+                        depth_of_loop++;
                 }
 #endif
                 if (rword == skip_more_for_this_rword && flag_skip) {
-                        /* it is "<false> && CMD" or "<true> || CMD"
-                         * and we should not execute CMD */
                         if (pi->followup == PIPE_SEQ)
                                 flag_skip = 0;
+                        /* it is "<false> && CMD" or "<true> || CMD"
+                         * and we should not execute CMD */
                         continue;
                 }
                 flag_skip = 1;
@@ -2277,15 +2280,13 @@ static int run_list(struct pipe *pi)
                                                 depth_break_continue--;
                                                 if (depth_break_continue == 0)
                                                         flag_break_continue = 0;
-                                                if (depth_break_continue != 0 || fbc == BC_BREAK)
-                                                        goto check_jobs_and_break;
-                                                /* "continue": simulate end of loop */
-                                                rword = RES_DONE;
-                                                continue;
-                                        }               
-                                        flag_break_continue = 0;
-                                        bb_error_msg("break/continue: only meaningful in a loop");
-                                        /* bash compat: exit code is still 0 */
+                                                /* else: e.g. "continue 2" should *break* once, *then* continue */
+                                        } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
+                                        if (depth_break_continue != 0 || fbc == BC_BREAK)
+                                                goto check_jobs_and_break;
+                                        /* "continue": simulate end of loop */
+                                        rword = RES_DONE;
+                                        continue;
                                 }
 #endif
                         } else if (pi->followup == PIPE_BG) {
@@ -2358,6 +2359,8 @@ static int run_list(struct pipe *pi)
 #endif
         debug_printf_exec("run_list lvl %d return %d\n", run_list_level + 1, rcode);
 #if ENABLE_HUSH_LOOPS
+        if (loop_top)
+                depth_of_loop--;
         free(for_list);
 #endif
 #if ENABLE_HUSH_CASE
@@ -4554,6 +4557,10 @@ static int builtin_unset(char **argv)
 #if ENABLE_HUSH_LOOPS
 static int builtin_break(char **argv)
 {
+        if (depth_of_loop == 0) {
+                bb_error_msg("%s: only meaningful in a loop", "break");
+                return EXIT_SUCCESS; /* bash compat */
+        }
         flag_break_continue++; /* BC_BREAK = 1 */
         depth_break_continue = 1;
         if (argv[1]) {
@@ -4564,12 +4571,18 @@ static int builtin_break(char **argv)
                         depth_break_continue = UINT_MAX;
                 }
         }
+        if (depth_of_loop > depth_break_continue)
+                depth_break_continue = depth_of_loop;
         return EXIT_SUCCESS;
 }
 
 static int builtin_continue(char **argv)
 {
-        flag_break_continue++; /* BC_CONTINUE = 2 = 1+1 */
-        return builtin_break(argv);
+        if (depth_of_loop) {
+                flag_break_continue++; /* BC_CONTINUE = 2 = 1+1 */
+                return builtin_break(argv);
+        }
+        bb_error_msg("%s: only meaningful in a loop", "continue");
+        return EXIT_SUCCESS; /* bash compat */
 }
 #endif
diff --git a/shell/hush_test/hush-misc/break5.right b/shell/hush_test/hush-misc/break5.right
new file mode 100644
index 000000000..0b9df2a4f
--- /dev/null
+++ b/shell/hush_test/hush-misc/break5.right
@@ -0,0 +1,13 @@
+A
+B
+0
+A:a
+B
+D
+A:b
+B
+D
+A:c
+B
+D
+0
diff --git a/shell/hush_test/hush-misc/break5.tests b/shell/hush_test/hush-misc/break5.tests
new file mode 100755
index 000000000..273e040ec
--- /dev/null
+++ b/shell/hush_test/hush-misc/break5.tests
@@ -0,0 +1,4 @@
+while true; do echo A; { echo B; break; echo C; }; echo D; done
+echo $?
+for v in a b c; do echo A:$v; (echo B; break; echo C); echo D; done
+echo $?