diff options
author | John Hawthorn <john.hawthorn@gmail.com> | 2016-06-07 01:58:41 -0700 |
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committer | John Hawthorn <john.hawthorn@gmail.com> | 2016-06-08 17:39:52 -0700 |
commit | 3b23f5714e5d4625117c52988edd972d3587db23 (patch) | |
tree | da47a606c12386b8c40165b2951c34f449a5005b /src/choices.c | |
parent | e176ba933813f9fc4c85a25aef8b53e7dd50859d (diff) |
Make sorting stable
C's stdlib's qsort isn't a stable sort. We want it to be so that any
equivalent matches are stored in the order they came in.
Diffstat (limited to 'src/choices.c')
-rw-r--r-- | src/choices.c | 17 |
1 files changed, 13 insertions, 4 deletions
diff --git a/src/choices.c b/src/choices.c index ba25749..d9445c5 100644 --- a/src/choices.c +++ b/src/choices.c @@ -15,12 +15,21 @@ static int cmpchoice(const void *_idx1, const void *_idx2) { const struct scored_result *a = _idx1; const struct scored_result *b = _idx2; - if (a->score == b->score) - return 0; - else if (a->score < b->score) + if (a->score == b->score) { + /* To ensure a stable sort, we must also sort by the string + * pointers. We can do this since we know all the stings are + * from a contiguous memory segment (buffer in choices_t). + */ + if (a->str < b->str) { + return -1; + } else { + return 1; + } + } else if (a->score < b->score) { return 1; - else + } else { return -1; + } } static void *safe_realloc(void *buffer, size_t size) { |