Re: [RFC/ PATCH 2/5] unpack_trees: group errors by type

[Junio C Hamano <gitster@pobox.com>]

Diane Gasselin <diane.gasselin@ensimag.imag.fr> writes:

> +/*
> + * Store error messages in an array, each case
> + * corresponding to a error message type
> + */
> +typedef enum {
> +	would_overwrite,
> +	not_uptodate_file,
> +	not_uptodate_dir,
> +	would_lose_untracked,
> +	would_lose_untracked_removed,
> +	sparse_not_uptodate_file
> +} unpack_trees_error;
> +#define NB_UNPACK_TREES_ERROR 6
> +struct rejected_files *unpack_rejects[NB_UNPACK_TREES_ERROR];

You folks seem to like global variables a lot...  Isn't there a struct
passed throughout the callchain in unpack_trees that you can attach this
information to?

Also "rejected_files" is not as technically correct (there are symlinks)
as "rejected_paths".

Style: we don't encourage "typedef enum { ... } unpack_trees_error";
instead we tend to just say "enum unpack_trees_error" both in the
definition and in the use.

> +	if (!porcelain) {
> +		error(msg,file,action);
> +		return -1;
> +	}

Style:
	if (!porcelain)
        	return error(msg, file, action);

> +static void free_rejected_files(unpack_trees_error e)
> +{
> +	while(unpack_rejects[e]->list) {

Style:
	while (unpack_rejects[e]->list) {

> +static void display_error_msgs()
> +{
> +	int i;
> +	int hasPorcelain = 0;

Style: we don't encourage camelCase.

Whichever way spelled, "has porcelain?" is puzzling.

Is this about "are we issuing error messages as a Porcelain program, or
are we a plumbing without noisy error messages?"  Or is this about "have
we said anything in the loop, and if so finish the message with
'Aborting'"?  If the former, I would name it after "we are Porcelain";
if the latter, I would name it after "we said something".

> +	for (i=0; i<NB_UNPACK_TREES_ERROR; i++) {

Style:

	for (i = 0; i < NB_UNPACK_TREES_ERROR; i++) {

> +		if (unpack_rejects[i] && unpack_rejects[i]->list) {
> +			hasPorcelain = 1;
> +			struct rejected_files_list *f = unpack_rejects[i]->list;
> +			char *action = unpack_rejects[i]->action;
> +			char *file = malloc(unpack_rejects[i]->size+1);
> +			*file = '\0';
> +			while (f) {
> +				strcat(file,"\t");
> +				strcat(file,f->file);
> +				strcat(file,"\n");
> +				f = f->next;
> +			}
> +			error(unpack_rejects[i]->msg,file,action);
> +			free_rejected_files(i);

It feels wrong to malloc() inside the loop (and without freeing, which is
worse).  At least the code should use strbuf to do something like:

	struct strbuf indented = STRBUF_INIT;
	for (f = unpack_rejects[i]->list; f; f = f->next)
                strbuf_addf(&indented, "\t%s\n", f->file);
	error(..., indented.buf, action);
        strbuf_release(&indented);