line-log: get rid of the parents array in process_ranges_merge_commit()

We can easily iterate through the parents of a merge commit without
turning the list of parents into a dynamically allocated array of
parents, so let's do so.  This way we can avoid a memory allocation
for each processed merge commit, though its effect on runtime seems to
be unmeasurable.

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/line-log.c b/line-log.c
index cf30915c942825d3e30634228cbd9ae5c11def12..b2a31ae956fee9d57c4adcd7f02e4da6a7b23e6b 100644 (file)
--- a/line-log.c
+++ b/line-log.c
@@ -1203,7 +1203,6 @@ static int process_ranges_merge_commit(struct rev_info *rev, struct commit *comm
                                       struct line_log_data *range)
 {
        struct line_log_data **cand;
-       struct commit **parents;
        struct commit_list *p;
        int i;
        int nparents = commit_list_count(commit->parents);
@@ -1213,15 +1212,15 @@ static int process_ranges_merge_commit(struct rev_info *rev, struct commit *comm
                nparents = 1;
 
        CALLOC_ARRAY(cand, nparents);
-       ALLOC_ARRAY(parents, nparents);
 
-       p = commit->parents;
-       for (i = 0; i < nparents; i++) {
+       for (p = commit->parents, i = 0;
+            p && i < nparents;
+            p = p->next, i++) {
+               struct commit *parent = p->item;
                struct diff_queue_struct diffqueue = DIFF_QUEUE_INIT;
                int changed;
-               parents[i] = p->item;
-               p = p->next;
-               queue_diffs(range, &rev->diffopt, &diffqueue, commit, parents[i]);
+
+               queue_diffs(range, &rev->diffopt, &diffqueue, commit, parent);
 
                changed = process_all_files(&cand[i], rev, &diffqueue, range);
                diff_queue_clear(&diffqueue);
@@ -1230,9 +1229,9 @@ static int process_ranges_merge_commit(struct rev_info *rev, struct commit *comm
                         * This parent can take all the blame, so we
                         * don't follow any other path in history
                         */
-                       add_line_range(rev, parents[i], cand[i]);
+                       add_line_range(rev, parent, cand[i]);
                        free_commit_list(commit->parents);
-                       commit_list_append(parents[i], &commit->parents);
+                       commit_list_append(parent, &commit->parents);
 
                        ret = 0;
                        goto out;
@@ -1243,14 +1242,15 @@ static int process_ranges_merge_commit(struct rev_info *rev, struct commit *comm
         * No single parent took the blame.  We add the candidates
         * from the above loop to the parents.
         */
-       for (i = 0; i < nparents; i++)
-               add_line_range(rev, parents[i], cand[i]);
+       for (p = commit->parents, i = 0;
+            p && i < nparents;
+            p = p->next, i++)
+               add_line_range(rev, p->item, cand[i]);
 
        ret = 1;
 
 out:
        clear_commit_line_range(rev, commit);
-       free(parents);
        for (i = 0; i < nparents; i++) {
                if (!cand[i])
                        continue;