libbb: introduce and use xrealloc_vector

function                                             old     new   delta
xrealloc_vector_helper                                 -      51     +51
create_list                                           84      99     +15
getopt_main                                          690     695      +5
passwd_main                                         1049    1053      +4
get_cached                                            85      89      +4
msh_main                                            1377    1380      +3
add_match                                             42      41      -1
read_lines                                           720     718      -2
grave                                               1068    1066      -2
fill_match_lines                                     143     141      -2
add_to_dirlist                                        67      65      -2
add_input_file                                        49      47      -2
act                                                  252     250      -2
fsck_main                                           2252    2246      -6
man_main                                             765     757      -8
bb_internal_initgroups                               228     220      -8
cut_main                                            1052    1041     -11
add_edge_to_node                                      55      43     -12
dpkg_main                                           3851    3835     -16
ifupdown_main                                       2202    2178     -24
sort_main                                            838     812     -26
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 5/15 up/down: 82/-124)          Total: -42 bytes

3 files changed, 7 insertions, 6 deletions

diff --git a/editors/awk.c b/editors/awk.c
index 2af39880e..7af9e1eeb 100644
--- a/editors/awk.c
+++ b/editors/awk.c
@@ -1473,8 +1473,10 @@ static regex_t *as_regex(node *op, regex_t *preg)
 /* gradually increasing buffer */
 static void qrealloc(char **b, int n, int *size)
 {
-	if (!*b || n >= *size)
-		*b = xrealloc(*b, *size = n + (n>>1) + 80);
+	if (!*b || n >= *size) {
+		*size = n + (n>>1) + 80;
+		*b = xrealloc(*b, *size);
+	}
 }
 
 /* resize field storage space */
diff --git a/editors/diff.c b/editors/diff.c
index 570c4c490..64ad6511d 100644
--- a/editors/diff.c
+++ b/editors/diff.c
@@ -1059,6 +1059,7 @@ static unsigned diffreg(char *file1, char *file2, int flags)
 
 	member = (int *) nfile[1];
 	equiv(sfile[0], slen[0], sfile[1], slen[1], member);
+//TODO: xrealloc_vector?
 	member = xrealloc(member, (slen[1] + 2) * sizeof(int));
 
 	class = (int *) nfile[0];
@@ -1168,8 +1169,7 @@ static int FAST_FUNC add_to_dirlist(const char *filename,
 		void *userdata,
 		int depth UNUSED_PARAM)
 {
-	/* +2: with space for eventual trailing NULL */
-	dl = xrealloc(dl, (dl_count+2) * sizeof(dl[0]));
+	dl = xrealloc_vector(dl, 5, dl_count);
 	dl[dl_count] = xstrdup(filename + (int)(ptrdiff_t)userdata);
 	dl_count++;
 	return TRUE;
diff --git a/editors/sed.c b/editors/sed.c
index 88bae785c..67e88418a 100644
--- a/editors/sed.c
+++ b/editors/sed.c
@@ -732,8 +732,7 @@ static void flush_append(void)
 
 static void add_input_file(FILE *file)
 {
-	G.input_file_list = xrealloc(G.input_file_list,
-			(G.input_file_count + 1) * sizeof(FILE *));
+	G.input_file_list = xrealloc_vector(G.input_file_list, 2, G.input_file_count);
 	G.input_file_list[G.input_file_count++] = file;
 }