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, 5 insertions, 6 deletions

diff --git a/util-linux/lsblk.c b/util-linux/lsblk.c
index a482bfbbc..3bd40bcb4 100644
--- a/util-linux/lsblk.c
+++ b/util-linux/lsblk.c
@@ -101,10 +101,10 @@ static char *get_mountpoints(const char *majmin)
 
         mountpoints = NULL;
         len = strlen(majmin);
-        p = G.mountinfo; // "/proc/self/mountinfo"
+        p = G.mountinfo; // contents of "/proc/self/mountinfo"
         /* lines a-la "63 1 259:3 / /MNTPOINT per-mount_options - ext4 /dev/NAME per-superblock_options" */
         while (*p) {
-                char *e, *f;
+                char *e;
 
                 p = skip_non_whitespace(p);
                 if (*p != ' ') break;
@@ -127,12 +127,11 @@ static char *get_mountpoints(const char *majmin)
                 // at " /MNTPOINT"
                 e = skip_non_whitespace(p + 1);
                 // e is at the end of " /MNTPOINT"
-                f = mountpoints;
 // NO. We return " /MNT1 /MNT2 /MNT3" _with_ leading space!
-//              if (!f)
+//              if (!mountpoints)
 //                      p++;
-                mountpoints = xasprintf("%s%.*s", f ? f : "", (int)(e - p), p);
-                free(f);
+                xasprintf_inplace(mountpoints, "%s%.*s",
+                        mountpoints ? mountpoints : "", (int)(e - p), p);
         }
         return mountpoints;
 }