Porting implementation of RFC json_preserve_fractional_part

Author: jrbasso

ext/json/json.c

@@ -102,6 +102,7 @@ static PHP_MINIT_FUNCTION(json)
 	REGISTER_LONG_CONSTANT("JSON_PRETTY_PRINT", PHP_JSON_PRETTY_PRINT, CONST_CS | CONST_PERSISTENT);
 	REGISTER_LONG_CONSTANT("JSON_UNESCAPED_UNICODE", PHP_JSON_UNESCAPED_UNICODE, CONST_CS | CONST_PERSISTENT);
 	REGISTER_LONG_CONSTANT("JSON_PARTIAL_OUTPUT_ON_ERROR", PHP_JSON_PARTIAL_OUTPUT_ON_ERROR, CONST_CS | CONST_PERSISTENT);
+	REGISTER_LONG_CONSTANT("JSON_PRESERVE_ZERO_FRACTION", PHP_JSON_PRESERVE_ZERO_FRACTION, CONST_CS | CONST_PERSISTENT);
 
 	REGISTER_LONG_CONSTANT("JSON_ERROR_NONE", PHP_JSON_ERROR_NONE, CONST_CS | CONST_PERSISTENT);
 	REGISTER_LONG_CONSTANT("JSON_ERROR_DEPTH", PHP_JSON_ERROR_DEPTH, CONST_CS | CONST_PERSISTENT);

ext/json/json_encoder.c

@@ -95,13 +95,18 @@ static inline void php_json_pretty_print_indent(smart_str *buf, int options) /*
 
 /* }}} */
 
-static inline void php_json_encode_double(smart_str *buf, double d) /* {{{ */
+static inline void php_json_encode_double(smart_str *buf, double d, int options) /* {{{ */
 {
 	if (!zend_isinf(d) && !zend_isnan(d)) {
 		size_t len;
 		char num[PHP_JSON_DOUBLE_MAX_LENGTH];
 		php_gcvt(d, EG(precision), '.', 'e', &num[0]);
 		len = strlen(num);
+		if (options & PHP_JSON_PRESERVE_ZERO_FRACTION && strchr(num, '.') == NULL && len < PHP_JSON_DOUBLE_MAX_LENGTH - 2) {
+			num[len++] = '.';
+			num[len++] = '0';
+			num[len] = '\0';
+		}
 		smart_str_appendl(buf, num, len);
 	} else {
 		JSON_G(error_code) = PHP_JSON_ERROR_INF_OR_NAN;
@@ -290,7 +295,7 @@ static void php_json_escape_string(smart_str *buf, char *s, size_t len, int opti
 			if (type == IS_LONG) {
 				smart_str_append_long(buf, p);
 			} else if (type == IS_DOUBLE) {
-				php_json_encode_double(buf, d);
+				php_json_encode_double(buf, d, options);
 			}
 			return;
 		}
@@ -502,7 +507,7 @@ void php_json_encode_zval(smart_str *buf, zval *val, int options) /* {{{ */
 			break;
 
 		case IS_DOUBLE:
-			php_json_encode_double(buf, Z_DVAL_P(val));
+			php_json_encode_double(buf, Z_DVAL_P(val), options);
 			break;
 
 		case IS_STRING:

ext/json/php_json.h

@@ -64,6 +64,7 @@ typedef enum {
 #define PHP_JSON_PRETTY_PRINT	(1<<7)
 #define PHP_JSON_UNESCAPED_UNICODE	(1<<8)
 #define PHP_JSON_PARTIAL_OUTPUT_ON_ERROR (1<<9)
+#define PHP_JSON_PRESERVE_ZERO_FRACTION (1<<10)
 
 /* Internal flags */
 #define PHP_JSON_OUTPUT_ARRAY	0

ext/json/tests/bug50224.phpt

@@ -0,0 +1,60 @@
+--TEST--
+bug #50224 (json_encode() does not always encode a float as a float)
+--SKIPIF--
+<?php if (!extension_loaded("json")) print "skip"; ?>
+--FILE--
+<?php
+echo "* Testing JSON output\n\n";
+var_dump(json_encode(12.3, JSON_PRESERVE_ZERO_FRACTION));
+var_dump(json_encode(12, JSON_PRESERVE_ZERO_FRACTION));
+var_dump(json_encode(12.0, JSON_PRESERVE_ZERO_FRACTION));
+var_dump(json_encode(0.0, JSON_PRESERVE_ZERO_FRACTION));
+var_dump(json_encode(array(12, 12.0, 12.3), JSON_PRESERVE_ZERO_FRACTION));
+var_dump(json_encode((object)array('float' => 12.0, 'integer' => 12), JSON_PRESERVE_ZERO_FRACTION));
+
+echo "\n* Testing encode/decode symmetry\n\n";
+
+var_dump(json_decode(json_encode(12.3, JSON_PRESERVE_ZERO_FRACTION)));
+var_dump(json_decode(json_encode(12, JSON_PRESERVE_ZERO_FRACTION)));
+var_dump(json_decode(json_encode(12.0, JSON_PRESERVE_ZERO_FRACTION)));
+var_dump(json_decode(json_encode(0.0, JSON_PRESERVE_ZERO_FRACTION)));
+var_dump(json_decode(json_encode(array(12, 12.0, 12.3), JSON_PRESERVE_ZERO_FRACTION)));
+var_dump(json_decode(json_encode((object)array('float' => 12.0, 'integer' => 12), JSON_PRESERVE_ZERO_FRACTION)));
+var_dump(json_decode(json_encode((object)array('float' => 12.0, 'integer' => 12), JSON_PRESERVE_ZERO_FRACTION), true));
+?>
+--EXPECTF--
+* Testing JSON output
+
+string(4) "12.3"
+string(2) "12"
+string(4) "12.0"
+string(3) "0.0"
+string(14) "[12,12.0,12.3]"
+string(27) "{"float":12.0,"integer":12}"
+
+* Testing encode/decode symmetry
+
+float(12.3)
+int(12)
+float(12)
+float(0)
+array(3) {
+  [0]=>
+  int(12)
+  [1]=>
+  float(12)
+  [2]=>
+  float(12.3)
+}
+object(stdClass)#%d (2) {
+  ["float"]=>
+  float(12)
+  ["integer"]=>
+  int(12)
+}
+array(2) {
+  ["float"]=>
+  float(12)
+  ["integer"]=>
+  int(12)
+}