Re: [PATCH v10 18/36] merge-recursive: add get_directory_renames()

> +static struct hashmap *get_directory_renames(struct diff_queue_struct *pairs,
> +					     struct tree *tree)
> +{
> +	struct hashmap *dir_renames;
> +	struct hashmap_iter iter;
> +	struct dir_rename_entry *entry;
> +	int i;
> +
> +	/*
> +	 * Typically, we think of a directory rename as all files from a
> +	 * certain directory being moved to a target directory.  However,
> +	 * what if someone first moved two files from the original
> +	 * directory in one commit, and then renamed the directory
> +	 * somewhere else in a later commit?  At merge time, we just know
> +	 * that files from the original directory went to two different
> +	 * places, and that the bulk of them ended up in the same place.
> +	 * We want each directory rename to represent where the bulk of the
> +	 * files from that directory end up; this function exists to find
> +	 * where the bulk of the files went.
> +	 *
> +	 * The first loop below simply iterates through the list of file
> +	 * renames, finding out how often each directory rename pair
> +	 * possibility occurs.
> +	 */
> +	dir_renames = xmalloc(sizeof(struct hashmap));

> +	dir_rename_init(dir_renames);
> +	for (i = 0; i < pairs->nr; ++i) {
> +		struct string_list_item *item;
> +		int *count;
> +		struct diff_filepair *pair = pairs->queue[i];
> +		char *old_dir, *new_dir;
> +
> +		/* File not part of directory rename if it wasn't renamed */
> +		if (pair->status != 'R')
> +			continue;
> +
> +		get_renamed_dir_portion(pair->one->path, pair->two->path,
> +					&old_dir,        &new_dir);
> +		if (!old_dir)
> +			/* Directory didn't change at all; ignore this one. */
> +			continue;
> +
> +		entry = dir_rename_find_entry(dir_renames, old_dir);
> +		if (!entry) {
> +			entry = xmalloc(sizeof(struct dir_rename_entry));