Fix for bug #10896 (0.00 > -0.00)

mysql-test/r/type_newdecimal.result:
  test result fixed
mysql-test/t/type_newdecimal.test:
  test case added
sql/my_decimal.h:
  we neede to check for zero here not to get -0.00

3 files changed, 27 insertions, 0 deletions

diff --git a/mysql-test/r/type_newdecimal.result b/mysql-test/r/type_newdecimal.result
index 09fbc6b8143..c0693d1585c 100644
--- a/mysql-test/r/type_newdecimal.result
+++ b/mysql-test/r/type_newdecimal.result
@@ -896,6 +896,8 @@ create table t1( d1 decimal(18) unsigned, d2 decimal(20) unsigned, d3 decimal (2
 insert into t1 values(1,-1,-1);
 ERROR 22003: Out of range value adjusted for column 'd2' at row 1
 drop table t1;
+set sql_mode='';
+set @sav_dpi= @@div_precision_increment;
 set @@div_precision_increment=15;
 create table t1 (col1 int, col2 decimal(30,25), col3 numeric(30,25));
 insert into t1 values (1,0.0123456789012345678912345,0.0123456789012345678912345);
@@ -909,3 +911,12 @@ select 77777777/7777777;
 77777777/7777777
 10.000000900000090
 drop table t1;
+set div_precision_increment= @sav_dpi;
+create table t1 (a decimal(4,2));
+insert into t1 values (0.00);
+select * from t1 where a > -0.00;
+a
+select * from t1 where a = -0.00;
+a
+0.00
+drop table t1;
diff --git a/mysql-test/t/type_newdecimal.test b/mysql-test/t/type_newdecimal.test
index 6bff6c22abc..d1d595285a2 100644
--- a/mysql-test/t/type_newdecimal.test
+++ b/mysql-test/t/type_newdecimal.test
@@ -934,10 +934,12 @@ create table t1( d1 decimal(18) unsigned, d2 decimal(20) unsigned, d3 decimal (2
 --error 1264
 insert into t1 values(1,-1,-1);
 drop table t1;
+set sql_mode='';
 
 #
 # Bug #8425 (insufficient precision of the division)
 #
+set @sav_dpi= @@div_precision_increment;
 set @@div_precision_increment=15;
 create table t1 (col1 int, col2 decimal(30,25), col3 numeric(30,25));
 insert into t1 values (1,0.0123456789012345678912345,0.0123456789012345678912345);
@@ -945,4 +947,13 @@ select col2/9999999999 from t1 where col1=1;
 select 9999999999/col2 from t1 where col1=1;
 select 77777777/7777777;
 drop table t1;
+set div_precision_increment= @sav_dpi;
 
+#
+# Bug #10896 (0.00 > -0.00)
+#
+create table t1 (a decimal(4,2));
+insert into t1 values (0.00);
+select * from t1 where a > -0.00;
+select * from t1 where a = -0.00;
+drop table t1;
diff --git a/sql/my_decimal.h b/sql/my_decimal.h
index 27fd33cffbe..b65e6aedaa2 100644
--- a/sql/my_decimal.h
+++ b/sql/my_decimal.h
@@ -290,6 +290,11 @@ int int2my_decimal(uint mask, longlong i, my_bool unsigned_flag, my_decimal *d)
 inline
 void my_decimal_neg(decimal_t *arg)
 {
+  if (decimal_is_zero(arg))
+  {
+    arg->sign= 0;
+    return;
+  }
   decimal_neg(arg);
 }