bc: do not allocate line editing state until needed

function                                             old     new   delta
xc_read_line                                         324     353     +29
free_line_input_t                                     34      39      +5
xc_vm_init                                           656     640     -16
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/1 up/down: 34/-16)             Total: 18 bytes

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

1 files changed, 11 insertions, 7 deletions

diff --git a/libbb/lineedit.c b/libbb/lineedit.c
index c3b5738e2..b3e7abac5 100644
--- a/libbb/lineedit.c
+++ b/libbb/lineedit.c
@@ -1417,15 +1417,19 @@ void FAST_FUNC show_history(const line_input_t *st)
                 printf("%4d %s\n", i, st->history[i]);
 }
 
+# if ENABLE_FEATURE_EDITING_SAVEHISTORY
 void FAST_FUNC free_line_input_t(line_input_t *n)
 {
-# if ENABLE_FEATURE_EDITING_SAVEHISTORY
-        int i = n->cnt_history;
-        while (i > 0)
-                free(n->history[--i]);
-#endif
-        free(n);
+        if (n) {
+                int i = n->cnt_history;
+                while (i > 0)
+                        free(n->history[--i]);
+                free(n);
+        }
 }
+# else
+/* #defined to free() in libbb.h */
+# endif
 
 # if ENABLE_FEATURE_EDITING_SAVEHISTORY
 /* We try to ensure that concurrent additions to the history
@@ -1506,7 +1510,7 @@ void save_history(line_input_t *st)
 {
         FILE *fp;
 
-        if (!st->hist_file)
+        if (!st || !st->hist_file)
                 return;
         if (st->cnt_history <= st->cnt_history_in_file)
                 return;