global: trivial conversions to fix -Wsign-compare warnings

We have a bunch of loops which iterate up to an unsigned boundary using
a signed index, which generates warnigs because we compare a signed and
unsigned value in the loop condition. Address these sites for trivial
cases and enable `-Wsign-compare` warnings for these code units.

This patch only adapts those code units where we can drop the
`DISABLE_SIGN_COMPARE_WARNINGS` macro in the same step.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: pks-t

advice.c

@@ -1,5 +1,3 @@
-#define DISABLE_SIGN_COMPARE_WARNINGS
-
 #include "git-compat-util.h"
 #include "advice.h"
 #include "config.h"
@@ -162,7 +160,6 @@ void advise_if_enabled(enum advice_type type, const char *advice, ...)
 int git_default_advice_config(const char *var, const char *value)
 {
 	const char *k, *slot_name;
-	int i;
 
 	if (!strcmp(var, "color.advice")) {
 		advice_use_color = git_config_colorbool(var, value);
@@ -181,7 +178,7 @@ int git_default_advice_config(const char *var, const char *value)
 	if (!skip_prefix(var, "advice.", &k))
 		return 0;
 
-	for (i = 0; i < ARRAY_SIZE(advice_setting); i++) {
+	for (size_t i = 0; i < ARRAY_SIZE(advice_setting); i++) {
 		if (strcasecmp(k, advice_setting[i].key))
 			continue;
 		advice_setting[i].level = git_config_bool(var, value)
@@ -195,9 +192,7 @@ int git_default_advice_config(const char *var, const char *value)
 
 void list_config_advices(struct string_list *list, const char *prefix)
 {
-	int i;
-
-	for (i = 0; i < ARRAY_SIZE(advice_setting); i++)
+	for (size_t i = 0; i < ARRAY_SIZE(advice_setting); i++)
 		list_config_item(list, prefix, advice_setting[i].key);
 }
 

base85.c

@@ -1,5 +1,3 @@
-#define DISABLE_SIGN_COMPARE_WARNINGS
-
 #include "git-compat-util.h"
 #include "base85.h"
 
@@ -31,10 +29,9 @@ static const char en85[] = {
 static char de85[256];
 static void prep_base85(void)
 {
-	int i;
 	if (de85['Z'])
 		return;
-	for (i = 0; i < ARRAY_SIZE(en85); i++) {
+	for (size_t i = 0; i < ARRAY_SIZE(en85); i++) {
 		int ch = en85[i];
 		de85[ch] = i + 1;
 	}

builtin/add.c

@@ -4,8 +4,6 @@
  * Copyright (C) 2006 Linus Torvalds
  */
 
-#define DISABLE_SIGN_COMPARE_WARNINGS
-
 #include "builtin.h"
 #include "advice.h"
 #include "config.h"
@@ -42,9 +40,9 @@ static int chmod_pathspec(struct repository *repo,
 			  char flip,
 			  int show_only)
 {
-	int i, ret = 0;
+	int ret = 0;
 
-	for (i = 0; i < repo->index->cache_nr; i++) {
+	for (size_t i = 0; i < repo->index->cache_nr; i++) {
 		struct cache_entry *ce = repo->index->cache[i];
 		int err;
 
@@ -72,9 +70,9 @@ static int renormalize_tracked_files(struct repository *repo,
 				     const struct pathspec *pathspec,
 				     int flags)
 {
-	int i, retval = 0;
+	int retval = 0;
 
-	for (i = 0; i < repo->index->cache_nr; i++) {
+	for (size_t i = 0; i < repo->index->cache_nr; i++) {
 		struct cache_entry *ce = repo->index->cache[i];
 
 		if (!include_sparse &&

builtin/branch.c

@@ -6,7 +6,6 @@
  */
 
 #define USE_THE_REPOSITORY_VARIABLE
-#define DISABLE_SIGN_COMPARE_WARNINGS
 
 #include "builtin.h"
 #include "config.h"

builtin/difftool.c

@@ -13,7 +13,6 @@
  */
 
 #define USE_THE_REPOSITORY_VARIABLE
-#define DISABLE_SIGN_COMPARE_WARNINGS
 
 #include "builtin.h"
 
@@ -367,7 +366,8 @@ static int run_dir_diff(const char *extcmd, int symlinks, const char *prefix,
 	char *lbase_dir = NULL, *rbase_dir = NULL;
 	size_t ldir_len, rdir_len, wtdir_len;
 	const char *workdir, *tmp;
-	int ret = 0, i;
+	int ret = 0;
+	size_t i;
 	FILE *fp = NULL;
 	struct hashmap working_tree_dups = HASHMAP_INIT(working_tree_entry_cmp,
 							NULL);

builtin/for-each-repo.c

@@ -1,5 +1,4 @@
 #define USE_THE_REPOSITORY_VARIABLE
-#define DISABLE_SIGN_COMPARE_WARNINGS
 
 #include "builtin.h"
 #include "config.h"
@@ -38,7 +37,7 @@ int cmd_for_each_repo(int argc,
 {
 	static const char *config_key = NULL;
 	int keep_going = 0;
-	int i, result = 0;
+	int result = 0;
 	const struct string_list *values;
 	int err;
 
@@ -63,7 +62,7 @@ int cmd_for_each_repo(int argc,
 	else if (err)
 		return 0;
 
-	for (i = 0; i < values->nr; i++) {
+	for (size_t i = 0; i < values->nr; i++) {
 		int ret = run_command_on_repo(values->items[i].string, argc, argv);
 		if (ret) {
 			if (!keep_going)

builtin/help.c

@@ -3,7 +3,6 @@
  */
 
 #define USE_THE_REPOSITORY_VARIABLE
-#define DISABLE_SIGN_COMPARE_WARNINGS
 
 #include "builtin.h"
 #include "config.h"
@@ -131,7 +130,6 @@ static void list_config_help(enum show_config_type type)
 	struct string_list keys = STRING_LIST_INIT_DUP;
 	struct string_list keys_uniq = STRING_LIST_INIT_DUP;
 	struct string_list_item *item;
-	int i;
 
 	for (p = config_name_list; *p; p++) {
 		const char *var = *p;
@@ -158,7 +156,7 @@ static void list_config_help(enum show_config_type type)
 			    e->prefix, e->placeholder);
 
 	string_list_sort(&keys);
-	for (i = 0; i < keys.nr; i++) {
+	for (size_t i = 0; i < keys.nr; i++) {
 		const char *var = keys.items[i].string;
 		const char *wildcard, *tag, *cut;
 		const char *dot = NULL;

builtin/mailsplit.c

@@ -175,15 +175,14 @@ static int split_maildir(const char *maildir, const char *dir,
 	char *file = NULL;
 	FILE *f = NULL;
 	int ret = -1;
-	int i;
 	struct string_list list = STRING_LIST_INIT_DUP;
 
 	list.cmp = maildir_filename_cmp;
 
 	if (populate_maildir_list(&list, maildir) < 0)
 		goto out;
 
-	for (i = 0; i < list.nr; i++) {
+	for (size_t i = 0; i < list.nr; i++) {
 		char *name;
 
 		free(file);

builtin/merge-tree.c

@@ -1,5 +1,4 @@
 #define USE_THE_REPOSITORY_VARIABLE
-#define DISABLE_SIGN_COMPARE_WARNINGS
 
 #include "builtin.h"
 #include "tree-walk.h"
@@ -499,10 +498,9 @@ static int real_merge(struct merge_tree_options *o,
 	if (!result.clean) {
 		struct string_list conflicted_files = STRING_LIST_INIT_NODUP;
 		const char *last = NULL;
-		int i;
 
 		merge_get_conflicted_files(&result, &conflicted_files);
-		for (i = 0; i < conflicted_files.nr; i++) {
+		for (size_t i = 0; i < conflicted_files.nr; i++) {
 			const char *name = conflicted_files.items[i].string;
 			struct stage_info *c = conflicted_files.items[i].util;
 			if (!o->name_only)
@@ -586,7 +584,7 @@ int cmd_merge_tree(int argc,
 
 	if (xopts.nr && o.mode == MODE_TRIVIAL)
 		die(_("--trivial-merge is incompatible with all other options"));
-	for (int x = 0; x < xopts.nr; x++)
+	for (size_t x = 0; x < xopts.nr; x++)
 		if (parse_merge_opt(&o.merge_options, xopts.v[x]))
 			die(_("unknown strategy option: -X%s"), xopts.v[x]);
 

builtin/pack-redundant.c

@@ -7,7 +7,6 @@
 */
 
 #define USE_THE_REPOSITORY_VARIABLE
-#define DISABLE_SIGN_COMPARE_WARNINGS
 
 #include "builtin.h"
 #include "gettext.h"
@@ -391,7 +390,6 @@ static int cmp_remaining_objects(const void *a, const void *b)
 static void sort_pack_list(struct pack_list **pl)
 {
 	struct pack_list **ary, *p;
-	int i;
 	size_t n = pack_list_size(*pl);
 
 	if (n < 2)
@@ -405,7 +403,7 @@ static void sort_pack_list(struct pack_list **pl)
 	QSORT(ary, n, cmp_remaining_objects);
 
 	/* link them back again */
-	for (i = 0; i < n - 1; i++)
+	for (size_t i = 0; i < n - 1; i++)
 		ary[i]->next = ary[i + 1];
 	ary[n - 1]->next = NULL;
 	*pl = ary[0];