Fix for bug #21205: Different number of digits for float/double/real in --ps-protocol

Various parts of code used different 'precision' arguments for sprintf("%g") when converting
floating point numbers to a string. This led to differences in results in some cases 
depending on whether the text-based or prepared statements protocol is used for a query.

Fixed by changing arguments to sprintf("%g") to always be 15 (DBL_DIG) so that results are
consistent regardless of the protocol.

This patch will be null-merged to 6.0 as the problem does not exists there (fixed by the
patch for WL#2934).

client/sql_string.cc:
  Use 15 (DBL_DIG) as a precision argument for sprintf(), as Field_double::val_str() does.
libmysql/libmysql.c:
  Use 15 (DBL_DIG) as a precision argument for sprintf(), as Field_double::val_str() does.
mysql-test/r/archive_gis.result:
  Fixed test results to take additional precision into account.
mysql-test/r/func_group.result:
  Fixed test results to take additional precision into account.
mysql-test/r/func_math.result:
  Fixed test results to take additional precision into account.
mysql-test/r/func_str.result:
  Fixed test results to take additional precision into account.
mysql-test/r/gis.result:
  Fixed test results to take additional precision into account.
mysql-test/r/innodb_gis.result:
  Fixed test results to take additional precision into account.
mysql-test/r/select.result:
  Fixed test results to take additional precision into account.
mysql-test/r/sp.result:
  Fixed test results to take additional precision into account.
mysql-test/r/type_float.result:
  Fixed test results to take additional precision into account.
mysql-test/t/type_float.test:
  Fixed test results to take additional precision into account.
sql/sql_string.cc:
  Use 15 (DBL_DIG) as a precision argument for sprintf(), as Field_double::val_str() does.

1 files changed, 5 insertions, 5 deletions

diff --git a/mysql-test/r/func_math.result b/mysql-test/r/func_math.result
index 150b6003dbe..0d7adbbba5e 100644
--- a/mysql-test/r/func_math.result
+++ b/mysql-test/r/func_math.result
@@ -60,7 +60,7 @@ Warnings:
 Note	1003	select ln(exp(10)) AS `ln(exp(10))`,exp((ln(sqrt(10)) * 2)) AS `exp(ln(sqrt(10))*2)`,ln(-(1)) AS `ln(-1)`,ln(0) AS `ln(0)`,ln(NULL) AS `ln(NULL)`
 select log2(8),log2(15),log2(-2),log2(0),log2(NULL);
 log2(8)	log2(15)	log2(-2)	log2(0)	log2(NULL)
-3	3.9068905956085	NULL	NULL	NULL
+3	3.90689059560852	NULL	NULL	NULL
 explain extended select log2(8),log2(15),log2(-2),log2(0),log2(NULL);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
@@ -68,7 +68,7 @@ Warnings:
 Note	1003	select log2(8) AS `log2(8)`,log2(15) AS `log2(15)`,log2(-(2)) AS `log2(-2)`,log2(0) AS `log2(0)`,log2(NULL) AS `log2(NULL)`
 select log10(100),log10(18),log10(-4),log10(0),log10(NULL);
 log10(100)	log10(18)	log10(-4)	log10(0)	log10(NULL)
-2	1.2552725051033	NULL	NULL	NULL
+2	1.25527250510331	NULL	NULL	NULL
 explain extended select log10(100),log10(18),log10(-4),log10(0),log10(NULL);
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
@@ -85,7 +85,7 @@ Note	1003	select pow(10,log10(10)) AS `pow(10,log10(10))`,pow(2,4) AS `power(2,4
 set @@rand_seed1=10000000,@@rand_seed2=1000000;
 select rand(999999),rand();
 rand(999999)	rand()
-0.014231365187309	0.028870999839968
+0.0142313651873091	0.028870999839968
 explain extended select rand(999999),rand();
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
@@ -101,7 +101,7 @@ Warnings:
 Note	1003	select pi() AS `pi()`,format(sin((pi() / 2)),6) AS `format(sin(pi()/2),6)`,format(cos((pi() / 2)),6) AS `format(cos(pi()/2),6)`,format(abs(tan(pi())),6) AS `format(abs(tan(pi())),6)`,format((1 / tan(1)),6) AS `format(cot(1),6)`,format(asin(1),6) AS `format(asin(1),6)`,format(acos(0),6) AS `format(acos(0),6)`,format(atan(1),6) AS `format(atan(1),6)`
 select degrees(pi()),radians(360);
 degrees(pi())	radians(360)
-180	6.2831853071796
+180	6.28318530717959
 SELECT ACOS(1.0);
 ACOS(1.0)
 0
@@ -321,7 +321,7 @@ mod(5, cast(-2 as unsigned))	mod(5, 18446744073709551614)	mod(5, -2)
 5	5	1
 select pow(cast(-2 as unsigned), 5), pow(18446744073709551614, 5), pow(-2, 5);
 pow(cast(-2 as unsigned), 5)	pow(18446744073709551614, 5)	pow(-2, 5)
-2.1359870359209e+96	2.1359870359209e+96	-32
+2.13598703592091e+96	2.13598703592091e+96	-32
 CREATE TABLE t1 (a timestamp, b varchar(20), c bit(1));
 INSERT INTO t1 VALUES('1998-09-23', 'str1', 1), ('2003-03-25', 'str2', 0);
 SELECT a DIV 900 y FROM t1 GROUP BY y;