hush: document better where bad redirect syntax is detected

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

diff --git a/shell/hush.c b/shell/hush.c
index a8ec54ec06b17e8841c93c576b852948ccf8e14d..e2b0a15b87b337a21777615759d869ecbb1736dd 100644 (file)
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -3054,6 +3054,14 @@ static int done_command(struct parse_context *ctx)
        struct pipe *pi = ctx->pipe;
        struct command *command = ctx->command;
 
+#if 0  /* Instead we emit error message at run time */
+       if (ctx->pending_redirect) {
+               /* For example, "cmd >" (no filename to redirect to) */
+               die_if_script("syntax error: %s", "invalid redirect");
+               ctx->pending_redirect = NULL;
+       }
+#endif
+
        if (command) {
                if (IS_NULL_CMD(command)) {
                        debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
@@ -3576,6 +3584,12 @@ static int parse_redirect(struct parse_context *ctx,
                debug_printf_parse("duplicating redirect '%d>&%d'\n",
                                redir->rd_fd, redir->rd_dup);
        } else {
+#if 0          /* Instead we emit error message at run time */
+               if (ctx->pending_redirect) {
+                       /* For example, "cmd > <file" */
+                       die_if_script("syntax error: %s", "invalid redirect");
+               }
+#endif
                /* Set ctx->pending_redirect, so we know what to do at the
                 * end of the next parsed word. */
                ctx->pending_redirect = redir;
@@ -6276,9 +6290,12 @@ static int setup_redirects(struct command *prog, int squirrel[])
                        /* "rd_fd<*>file" case (<*> is <,>,>>,<>) */
                        char *p;
                        if (redir->rd_filename == NULL) {
-                               /* Something went wrong in the parse.
-                                * Pretend it didn't happen */
-                               bb_error_msg("bug in redirect parse");
+                               /*
+                                * Examples:
+                                * "cmd >" (no filename)
+                                * "cmd > <file" (2nd redirect starts too early)
+                                */
+                               die_if_script("syntax error: %s", "invalid redirect");
                                continue;
                        }
                        mode = redir_table[redir->rd_type].mode;