bc: fix for() to not leave data on stack

function                                             old     new   delta
zbc_parse_stmt_possibly_auto                        1665    1697     +32
zbc_vm_process                                       672     701     +29
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/0 up/down: 61/0)               Total: 61 bytes
   text	   data	    bss	    dec	    hex	filename
 981656	    485	   7296	 989437	  f18fd	busybox_old
 981748	    485	   7296	 989529	  f1959	busybox_unstripped

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

1 files changed, 15 insertions, 0 deletions

diff --git a/testsuite/bc.tests b/testsuite/bc.tests
index edff209bb..b3ce894ee 100755
--- a/testsuite/bc.tests
+++ b/testsuite/bc.tests
@@ -56,6 +56,21 @@ testing "bc for(;;)" \
         "2\n3\n2\n9\n" \
         "" "i=2; for (;;) { 2; if(--i==0) break; 3; }; 9"
 
+testing "bc for (;cond;)" \
+        "bc" \
+        "1\n2\n3\n9\n" \
+        "" "i=0; for(;i<3;)++i; 9"
+
+testing "bc for (;cond;upd)" \
+        "bc" \
+        "1\n2\n3\n9\n" \
+        "" "i=1; for(;i<4;i++)i; 9"
+
+testing "bc for (init;cond;upd)" \
+        "bc" \
+        "1\n2\n3\n9\n" \
+        "" "for(i=1;i<4;i++)i; 9"
+
 testing "bc define auto" \
         "bc" \
         "8\n9\n" \