hush: fix and_or_and_backgrounding.tests failure

function                                             old     new   delta
done_pipe                                            133     218     +85

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

5 files changed, 71 insertions, 1 deletions

diff --git a/shell/hush_test/hush-bugs/and_or_and_backgrounding.right b/shell/ash_test/ash-parsing/and_or_and_backgrounding.right
index 90ce63e01..90ce63e01 100644
--- a/shell/hush_test/hush-bugs/and_or_and_backgrounding.right
+++ b/shell/ash_test/ash-parsing/and_or_and_backgrounding.right
diff --git a/shell/hush_test/hush-bugs/and_or_and_backgrounding.tests b/shell/ash_test/ash-parsing/and_or_and_backgrounding.tests
index 05acfb863..05acfb863 100755
--- a/shell/hush_test/hush-bugs/and_or_and_backgrounding.tests
+++ b/shell/ash_test/ash-parsing/and_or_and_backgrounding.tests
diff --git a/shell/hush.c b/shell/hush.c
index b76351fde..2a734f3de 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -3373,12 +3373,47 @@ static void done_pipe(struct parse_context *ctx, pipe_style type)
         debug_printf_parse("done_pipe entered, followup %d\n", type);
         /* Close previous command */
         not_null = done_command(ctx);
-        ctx->pipe->followup = type;
 #if HAS_KEYWORDS
         ctx->pipe->pi_inverted = ctx->ctx_inverted;
         ctx->ctx_inverted = 0;
         ctx->pipe->res_word = ctx->ctx_res_w;
 #endif
+        if (type != PIPE_BG || ctx->list_head == ctx->pipe) {
+ no_conv:
+                ctx->pipe->followup = type;
+        } else {
+                /* Necessary since && and || have more precedence than &:
+                 * "cmd1 && cmd2 &" must spawn both cmds, not only cmd2,
+                 * in a backgrounded subshell.
+                 */
+                struct pipe *pi;
+                struct command *command;
+
+                /* Is this actually the case? */
+                pi = ctx->list_head;
+                while (pi != ctx->pipe) {
+                        if (pi->followup != PIPE_AND && pi->followup != PIPE_OR)
+                                goto no_conv;
+                        pi = pi->next;
+                }
+
+                debug_printf_parse("BG with more than one pipe, converting to { p1 &&...pN; } &\n");
+                pi->followup = PIPE_SEQ; /* close pN _not_ with "&"! */
+                pi = xzalloc(sizeof(*pi));
+                pi->followup = PIPE_BG;
+                pi->num_cmds = 1;
+                pi->cmds = xzalloc(sizeof(pi->cmds[0]));
+                command = &pi->cmds[0];
+                if (CMD_NORMAL != 0) /* "if xzalloc didn't do that already" */
+                        command->cmd_type = CMD_NORMAL;
+                command->group = ctx->list_head;
+#if !BB_MMU
+//TODO: is this correct?!
+                command->group_as_string = xstrdup(ctx->as_string.data);
+#endif
+                /* Replace all pipes in ctx with one newly created */
+                ctx->list_head = ctx->pipe = pi;
+        }
 
         /* Without this check, even just <enter> on command line generates
          * tree of three NOPs (!). Which is harmless but annoying.
diff --git a/shell/hush_test/hush-parsing/and_or_and_backgrounding.right b/shell/hush_test/hush-parsing/and_or_and_backgrounding.right
new file mode 100644
index 000000000..90ce63e01
--- /dev/null
+++ b/shell/hush_test/hush-parsing/and_or_and_backgrounding.right
@@ -0,0 +1,4 @@
+First
+Second
+Third
+Done
diff --git a/shell/hush_test/hush-parsing/and_or_and_backgrounding.tests b/shell/hush_test/hush-parsing/and_or_and_backgrounding.tests
new file mode 100755
index 000000000..05acfb863
--- /dev/null
+++ b/shell/hush_test/hush-parsing/and_or_and_backgrounding.tests
@@ -0,0 +1,31 @@
+# UNFIXED BUG: hush thinks that ; && || & have the same precedence.
+# According to this doc, && || have higher precedence than ; &.
+# See example below.
+# Precedence of ; is not a problem in practice. Precedence of & is.
+#
+#http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
+#
+#2.9.3 Lists
+#
+#An AND-OR list is a sequence of one or more pipelines separated by
+#the operators "&&" and "||" .
+#
+#A list is a sequence of one or more AND-OR lists separated by the operators
+#';' and '&' and optionally terminated by ';', '&', or <newline>.
+#
+#The operators "&&" and "||" shall have equal precedence and shall be
+#evaluated with left associativity. For example, both of the following
+#commands write solely bar to standard output:
+#
+#    false && echo foo || echo bar
+#    true || echo foo && echo bar
+#
+#A ';' or <newline> terminator shall cause the preceding AND-OR list
+#to be executed sequentially; an '&' shall cause asynchronous execution
+#of the preceding AND-OR list.
+
+echo First && sleep 0.2 && echo Third &
+sleep 0.1
+echo Second
+wait
+echo Done