Apply some of the fixes from PR #740, although by using size_t instead of castings.

apps/json_parse.c

@@ -63,7 +63,7 @@ static int parseit(int fd, int (*callback)(struct json_object *))
 {
 	struct json_object *obj;
 	char buf[32768];
-	int ret;
+	ssize_t ret;
 	int depth = JSON_TOKENER_DEFAULT_DEPTH;
 	json_tokener *tok;
 
@@ -86,20 +86,21 @@ static int parseit(int fd, int (*callback)(struct json_object *))
 	size_t total_read = 0;
 	while ((ret = read(fd, buf, sizeof(buf))) > 0)
 	{
-		total_read += ret;
-		int start_pos = 0;
-		while (start_pos != ret)
+		size_t retu = (size_t)ret;  // We know it's positive
+		total_read += retu;
+		size_t start_pos = 0;
+		while (start_pos != retu)
 		{
-			obj = json_tokener_parse_ex(tok, &buf[start_pos], ret - start_pos);
+			obj = json_tokener_parse_ex(tok, &buf[start_pos], retu - start_pos);
 			enum json_tokener_error jerr = json_tokener_get_error(tok);
-			int parse_end = json_tokener_get_parse_end(tok);
+			size_t parse_end = json_tokener_get_parse_end(tok);
 			if (obj == NULL && jerr != json_tokener_continue)
 			{
 				const char *aterr = (start_pos + parse_end < (int)sizeof(buf)) ?
 					&buf[start_pos + parse_end] : "";
 				fflush(stdout);
-				int fail_offset = total_read - ret + start_pos + parse_end;
-				fprintf(stderr, "Failed at offset %d: %s %c\n", fail_offset,
+				size_t fail_offset = total_read - retu + start_pos + parse_end;
+				fprintf(stderr, "Failed at offset %lu: %s %c\n", (unsigned long)fail_offset,
 				        json_tokener_error_desc(jerr), aterr[0]);
 				json_tokener_free(tok);
 				return 1;
@@ -115,7 +116,7 @@ static int parseit(int fd, int (*callback)(struct json_object *))
 				}
 			}
 			start_pos += json_tokener_get_parse_end(tok);
-			assert(start_pos <= ret);
+			assert(start_pos <= retu);
 		}
 	}
 	if (ret < 0)

json_pointer.c

@@ -29,8 +29,8 @@
 
 static void string_replace_all_occurrences_with_char(char *s, const char *occur, char repl_char)
 {
-	int slen = strlen(s);
-	int skip = strlen(occur) - 1; /* length of the occurrence, minus the char we're replacing */
+	size_t slen = strlen(s);
+	size_t skip = strlen(occur) - 1; /* length of the occurrence, minus the char we're replacing */
 	char *p = s;
 	while ((p = strstr(p, occur)))
 	{
@@ -41,9 +41,9 @@ static void string_replace_all_occurrences_with_char(char *s, const char *occur,
 	}
 }
 
-static int is_valid_index(struct json_object *jo, const char *path, int32_t *idx)
+static int is_valid_index(struct json_object *jo, const char *path, size_t *idx)
 {
-	int i, len = strlen(path);
+	size_t i, len = strlen(path);
 	/* this code-path optimizes a bit, for when we reference the 0-9 index range
 	 * in a JSON array and because leading zeros not allowed
 	 */
@@ -73,12 +73,14 @@ static int is_valid_index(struct json_object *jo, const char *path, int32_t *idx
 		}
 	}
 
-	*idx = strtol(path, NULL, 10);
-	if (*idx < 0)
+	long int idx_val = strtol(path, NULL, 10);
+	if (idx_val < 0)
 	{
 		errno = EINVAL;
 		return 0;
 	}
+	*idx = idx_val;
+
 check_oob:
 	len = json_object_array_length(jo);
 	if (*idx >= len)
@@ -95,7 +97,7 @@ static int json_pointer_get_single_path(struct json_object *obj, char *path,
 {
 	if (json_object_is_type(obj, json_type_array))
 	{
-		int32_t idx;
+		size_t idx;
 		if (!is_valid_index(obj, path, &idx))
 			return -1;
 		obj = json_object_array_get_idx(obj, idx);
@@ -128,7 +130,7 @@ static int json_pointer_set_single_path(struct json_object *parent, const char *
 {
 	if (json_object_is_type(parent, json_type_array))
 	{
-		int32_t idx;
+		size_t idx;
 		/* RFC (Chapter 4) states that '-' may be used to add new elements to an array */
 		if (path[0] == '-' && path[1] == '\0')
 			return json_object_array_add(parent, value);

json_util.c

@@ -85,7 +85,7 @@ struct json_object *json_object_from_fd_ex(int fd, int in_depth)
 	struct printbuf *pb;
 	struct json_object *obj;
 	char buf[JSON_FILE_BUF_SIZE];
-	int ret;
+	ssize_t ret;
 	int depth = JSON_TOKENER_DEFAULT_DEPTH;
 	json_tokener *tok;
 
@@ -107,12 +107,15 @@ struct json_object *json_object_from_fd_ex(int fd, int in_depth)
 		return NULL;
 	}
 
-	while ((ret = read(fd, buf, JSON_FILE_BUF_SIZE)) > 0)
+	while ((ret = read(fd, buf, sizeof(buf))) > 0)
 	{
 		if (printbuf_memappend(pb, buf, ret) < 0)
 		{
-			_json_c_set_last_err("json_object_from_fd_ex: error reading fd %d: %s\n",
-			                     fd, strerror(errno));
+#if JSON_FILE_BUF_SIZE > INT_MAX
+#error "Can't append more than INT_MAX bytes at a time"
+#endif
+			_json_c_set_last_err(
+		    	"json_object_from_fd_ex: failed to printbuf_memappend after reading %d+%d bytes: %s", printbuf_length(pb), (int)ret, strerror(errno));
 			json_tokener_free(tok);
 			printbuf_free(pb);
 			return NULL;
@@ -191,9 +194,9 @@ int json_object_to_fd(int fd, struct json_object *obj, int flags)
 }
 static int _json_object_to_fd(int fd, struct json_object *obj, int flags, const char *filename)
 {
-	int ret;
+	ssize_t ret;
 	const char *json_str;
-	unsigned int wpos, wsize;
+	size_t wpos, wsize;
 
 	filename = filename ? filename : "(fd)";
 
@@ -202,8 +205,7 @@ static int _json_object_to_fd(int fd, struct json_object *obj, int flags, const
 		return -1;
 	}
 
-	/* CAW: probably unnecessary, but the most 64bit safe */
-	wsize = (unsigned int)(strlen(json_str) & UINT_MAX);
+	wsize = strlen(json_str);
 	wpos = 0;
 	while (wpos < wsize)
 	{
@@ -215,7 +217,7 @@ static int _json_object_to_fd(int fd, struct json_object *obj, int flags, const
 		}
 
 		/* because of the above check for ret < 0, we can safely cast and add */
-		wpos += (unsigned int)ret;
+		wpos += (size_t)ret;
 	}
 
 	return 0;

tests/test_parse.c

@@ -38,7 +38,7 @@ static void do_clear_serializer(json_object *jso);
 
 static void single_incremental_parse(const char *test_string, int clear_serializer)
 {
-	int ii;
+	size_t ii;
 	int chunksize = atoi(getenv("TEST_PARSE_CHUNKSIZE"));
 	struct json_tokener *tok;
 	enum json_tokener_error jerr;
@@ -53,7 +53,7 @@ static void single_incremental_parse(const char *test_string, int clear_serializ
 	all_at_once_str = json_object_to_json_string(all_at_once_obj);
 
 	tok = json_tokener_new();
-	int test_string_len = strlen(test_string) + 1; // Including '\0' !
+	size_t test_string_len = strlen(test_string) + 1; // Including '\0' !
 	for (ii = 0; ii < test_string_len; ii += chunksize)
 	{
 		int len_to_parse = chunksize;