Fix for bugs #68114 (Build fails on OS X due to undefined symbols)

and #68657 (Reading 4 byte floats with Mysqli and libmysqlclient
has rounding errors).

The patch removes support for Decimal floating point numbers and
now defaults to using similar logic as what libmysqlclient does:
convert a 4 byte floating point number into a string, and then the
string into a double. The quirks of MySQL are maintained as seen in
Field_Float::val_str()

1 files changed, 55 insertions, 0 deletions

diff --git a/ext/standard/float_to_double.c b/ext/standard/float_to_double.c
new file mode 100644
index 0000000000..5aff1fe9c4
--- /dev/null
+++ b/ext/standard/float_to_double.c
@@ -0,0 +1,55 @@
+/*
+  +----------------------------------------------------------------------+
+  | PHP Version 5                                                        |
+  +----------------------------------------------------------------------+
+  | Copyright (c) 2006-2014 The PHP Group                                |
+  +----------------------------------------------------------------------+
+  | This source file is subject to version 3.01 of the PHP license,      |
+  | that is bundled with this package in the file LICENSE, and is        |
+  | available through the world-wide-web at the following url:           |
+  | http://www.php.net/license/3_01.txt                                  |
+  | If you did not receive a copy of the PHP license and are unable to   |
+  | obtain it through the world-wide-web, please send a note to          |
+  | license@php.net so we can mail you a copy immediately.               |
+  +----------------------------------------------------------------------+
+  | Authors: Keyur Govande <kgovande@gmail.com>                          |
+  +----------------------------------------------------------------------+
+*/
+
+#include <float.h>
+#include "float_to_double.h"
+#include "main/snprintf.h"
+
+#define MAX_BUF_LEN 255
+
+#ifndef FLT_DIG
+# define FLT_DIG 6
+#endif
+
+/*
+ * Convert from a 4-byte float to a 8-byte decimal by first converting
+ * the float to a string, and then the string to a double.
+ * The decimals argument specifies the precision of the output. If decimals
+ * is less than zero, then a gcvt(3) like logic is used with the significant
+ * digits set to FLT_DIG i.e. 6.
+ */
+double float_to_double(float fp4, int decimals) {
+	char num_buf[MAX_BUF_LEN]; /* Over allocated */
+
+	if (decimals < 0) {
+		php_gcvt(fp4, FLT_DIG, '.', 'e', num_buf);
+	} else {
+		php_sprintf(num_buf, "%.*f", decimals, fp4);
+	}
+
+	return zend_strtod(num_buf, NULL);
+}
+
+/*
+ * Local variables:
+ * tab-width: 4
+ * c-basic-offset: 4
+ * End:
+ * vim600: noet sw=4 ts=4 fdm=marker
+ * vim<600: noet sw=4 ts=4
+ */