libbb: introduce and use xasprintf_inplace()

function                                             old     new   delta
xasprintf_and_free                                     -      49     +49
watch_main                                           269     282     +13
singlemount                                         1313    1315      +2
append_mount_options                                 157     149      -8
ip_port_str                                          122     112     -10
lsblk_main                                           869     858     -11
add_cmd                                             1178    1167     -11
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 2/4 up/down: 64/-40)             Total: 24 bytes

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

1 files changed, 2 insertions, 3 deletions

diff --git a/editors/sed.c b/editors/sed.c
index 6179c5e80..029e9b8e7 100644
--- a/editors/sed.c
+++ b/editors/sed.c
@@ -657,9 +657,8 @@ static void add_cmd(const char *cmdstr)
 
         /* Append this line to any unfinished line from last time. */
         if (G.add_cmd_line) {
-                char *tp = xasprintf("%s\n%s", G.add_cmd_line, cmdstr);
-                free(G.add_cmd_line);
-                cmdstr = G.add_cmd_line = tp;
+                cmdstr = xasprintf_inplace(G.add_cmd_line,
+                        "%s\n%s", G.add_cmd_line, cmdstr);
         }
 
         /* If this line ends with unescaped backslash, request next line. */