Re: [GSoC PATCH v3] rm: fix sign comparison warnings

> There are multiple places in loops, where a signed and an
> unsigned data type are compared. Git uses a mix of signed and unsigned
> types to store lengths of arrays. This sometimes leads to using a signed
> index for an array whose length is stored in an unsigned variable or
> vice versa.
> 
> get_ours_cache_pos is a special case where i, though derived from a
> signed variable is never negative. Move this part to the caller side
> and make i an unsigned argument of the function. Rename i to
> pos to make it descriptive, now that it is a function argument.
> 
> Replace signed data types with unsigned data types and vice versa
> wherever necessary. Where both signed and unsigned data types have been
> used, define a new variable in the scope of the for loop for use as the
> iterator. Remove #define DISABLE_SIGN_COMPARE_WARNINGS.
> 
> Signed-off-by: Arnav Bhate <bhatearnav@gmail.com>
> ---
>  builtin/rm.c | 21 +++++++++------------
>  1 file changed, 9 insertions(+), 12 deletions(-)
> 
> diff --git a/builtin/rm.c b/builtin/rm.c
> index 12ae086a55..a5c9fc644e 100644
> --- a/builtin/rm.c
> +++ b/builtin/rm.c
> @@ -5,7 +5,6 @@
>   */
>  
>  #define USE_THE_REPOSITORY_VARIABLE
> -#define DISABLE_SIGN_COMPARE_WARNINGS
>  
>  #include "builtin.h"
>  #include "advice.h"
> @@ -40,14 +39,12 @@ static struct {
>  	} *entry;
>  } list;
>  
> -static int get_ours_cache_pos(const char *path, int pos)
> +static int get_ours_cache_pos(const char *path, unsigned int inverted_pos)
>  {
> -	int i = -pos - 1;
> -
> -	while ((i < the_repository->index->cache_nr) && !strcmp(the_repository->index->cache[i]->name, path)) {
> -		if (ce_stage(the_repository->index->cache[i]) == 2)
> -			return i;
> -		i++;
> +	while ((inverted_pos < the_repository->index->cache_nr) && !strcmp(the_repository->index->cache[inverted_pos]->name, path)) {
> +		if (ce_stage(the_repository->index->cache[inverted_pos]) == 2)
> +			return inverted_pos;
> +		inverted_pos++;
>  	}
>  	return -1;
>  }
> @@ -58,7 +55,7 @@ static void print_error_files(struct string_list *files_list,
>  			      int *errs)
>  {
>  	if (files_list->nr) {
> -		int i;
> +		unsigned int i;
>  		struct strbuf err_msg = STRBUF_INIT;
>  
>  		strbuf_addstr(&err_msg, main_msg);
> @@ -83,7 +80,7 @@ static void submodules_absorb_gitdir_if_needed(void)
>  
>  		pos = index_name_pos(the_repository->index, name, strlen(name));
>  		if (pos < 0) {
> -			pos = get_ours_cache_pos(name, pos);
> +			pos = get_ours_cache_pos(name, -pos - 1);
>  			if (pos < 0)
>  				continue;
>  		}
> @@ -131,7 +128,7 @@ static int check_local_mod(struct object_id *head, int index_only)
>  			 * Skip unmerged entries except for populated submodules
>  			 * that could lose history when removed.
>  			 */
> -			pos = get_ours_cache_pos(name, pos);
> +			pos = get_ours_cache_pos(name, -pos - 1);
>  			if (pos < 0)
>  				continue;
>  
> @@ -314,7 +311,7 @@ int cmd_rm(int argc,
>  	if (pathspec_needs_expanded_index(the_repository->index, &pathspec))
>  		ensure_full_index(the_repository->index);
>  
> -	for (i = 0; i < the_repository->index->cache_nr; i++) {
> +	for (unsigned int i = 0; i < the_repository->index->cache_nr; i++) {
>  		const struct cache_entry *ce = the_repository->index->cache[i];
>  
>  		if (!include_sparse &&