bk commit into 5.0 tree (hf:1.1941) BUG#10632

[holyfoot]

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5.0 repository of hf. When hf does a push these changes will
be propagated to the main repository and, within 24 hours after the
push, to the public repository.
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ChangeSet
  1.1941 05/06/15 19:53:40 hf@deer.(none) +3 -0
  Fix for bug #10632 (CEILING returns wrong result)

  strings/decimal.c
    1.53 05/06/15 19:52:42 hf@deer.(none) +25 -4
    handling of round_digit changed - we have to check all the digits after
    the point if round_digit is 0

  mysql-test/t/func_math.test
    1.19 05/06/15 19:52:41 hf@deer.(none) +7 -0
    test case added

  mysql-test/r/func_math.result
    1.27 05/06/15 19:52:41 hf@deer.(none) +6 -0
    test result fixed

# This is a BitKeeper patch.  What follows are the unified diffs for the
# set of deltas contained in the patch.  The rest of the patch, the part
# that BitKeeper cares about, is below these diffs.
# User:	hf
# Host:	deer.(none)
# Root:	/home/hf/work/mysql-5.0.10632

--- 1.26/mysql-test/r/func_math.result	Thu Jun  9 15:26:47 2005
+++ 1.27/mysql-test/r/func_math.result	Wed Jun 15 19:52:41 2005
@@ -146,3 +146,9 @@
 select round(150, 2);
 round(150, 2)
 150.00
+select ceil(0.09);
+ceil(0.09)
+1
+select ceil(0.000000000000000009);
+ceil(0.000000000000000009)
+1

--- 1.18/mysql-test/t/func_math.test	Thu Jun  9 15:26:47 2005
+++ 1.19/mysql-test/t/func_math.test	Wed Jun 15 19:52:41 2005
@@ -84,3 +84,10 @@
 # Bug #10083 (round doesn't increase decimals)
 #
 select round(150, 2);
+
+#
+# Bug @10632 (Ceiling function returns wrong answer)
+#
+select ceil(0.09);
+select ceil(0.000000000000000009);
+

--- 1.52/strings/decimal.c	Thu Jun  9 12:42:55 2005
+++ 1.53/strings/decimal.c	Wed Jun 15 19:52:42 2005
@@ -1490,11 +1490,31 @@
   buf1+=intg0+frac0-1;
   if (scale == frac0*DIG_PER_DEC1)
   {
+    int do_inc= FALSE;
     DBUG_ASSERT(frac0+intg0 >= 0);
-    x=buf0[1]/DIG_MASK;
-    if (x > round_digit ||
-        (round_digit == 5 && x == 5 && (mode == HALF_UP ||
-             (frac0+intg0 > 0 && *buf0 & 1))))
+    switch (round_digit)
+    {
+    case 0:
+    {
+      dec1 *p0= buf0 + (frac1-frac0);
+      for (; p0 > buf0; p0--)
+        if (*p0)
+        {
+          do_inc= TRUE;
+          break;
+        };
+      break;
+    }
+    case 5:
+    {
+      x= buf0[1]/DIG_MASK;
+      do_inc= (x>5) || ((x == 5) &&
+                        (mode == HALF_UP || (frac0+intg0 > 0 && *buf0 &
1)));
+      break;
+    };
+    default:;
+    };
+    if (do_inc)
     {
       if (frac0+intg0>0)
         (*buf1)++;
@@ -1509,6 +1529,7 @@
   }
   else
   {
+    /* TODO - fix this code as it won't work for CEILING mode */
     int pos=frac0*DIG_PER_DEC1-scale-1;
     DBUG_ASSERT(frac0+intg0 > 0);
     x=*buf1 / powers10[pos];