From 0fc68ab8eac79fa1521659a6c67c635ae7cc678c Mon Sep 17 00:00:00 2001
From: AlexPeshkoff <peshkoff@mail.ru>
Date: Wed, 15 Mar 2017 14:42:30 +0300
Subject: [PATCH] Avoid loosing decimal float precision, scale and/or sign info
 when sorting

---
 src/common/DecFloat.cpp         | 18 +++++++++++-------
 src/jrd/opt.cpp                 |  3 ++-
 src/jrd/recsrc/SortedStream.cpp |  2 +-
 3 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/src/common/DecFloat.cpp b/src/common/DecFloat.cpp
index c3ee05870b..5a5ea1acd6 100644
--- a/src/common/DecFloat.cpp
+++ b/src/common/DecFloat.cpp
@@ -140,11 +140,17 @@ void make(unsigned int* key,
 	unsigned dig = digits(pMax, coeff, exp);
 
 	// exponent bias and sign
-	exp += (bias + 2);
 	if (!dig)
-		exp = 1;
-	if (sign)
-		exp = -exp;
+	{
+		exp = 0;
+		sign = 0;
+	}
+	else
+	{
+		exp += (bias + 2);
+		if (sign)
+			exp = -exp;
+	}
 	*key++ = exp;
 
 	// convert to SLONG
@@ -171,9 +177,7 @@ void grab(unsigned int* key,
 		sign = DECFLOAT_Sign;
 		exp = -exp;
 	}
-	if (exp == 1)
-		exp = 0;
-	else
+	if (exp != 0)
 		exp -= (bias + 2);
 
 	// convert from SLONG
diff --git a/src/jrd/opt.cpp b/src/jrd/opt.cpp
index e298bad4a1..b37f8e5571 100644
--- a/src/jrd/opt.cpp
+++ b/src/jrd/opt.cpp
@@ -2453,7 +2453,8 @@ SortedStream* OPT_gen_sort(thread_db* tdbb, CompilerScratch* csb, const StreamLi
 						fieldNode->getDesc(tdbb, csb, desc);
 
 						// International type text has a computed key
-						if (IS_INTL_DATA(desc))
+						// Different decimal float values sometimes have same keys
+						if (IS_INTL_DATA(desc) || desc->isDecFloat())
 							break;
 
 						--items;
diff --git a/src/jrd/recsrc/SortedStream.cpp b/src/jrd/recsrc/SortedStream.cpp
index 9cc24c7e8c..8a518daf63 100644
--- a/src/jrd/recsrc/SortedStream.cpp
+++ b/src/jrd/recsrc/SortedStream.cpp
@@ -339,7 +339,7 @@ void SortedStream::mapData(thread_db* tdbb, jrd_req* request, UCHAR* data) const
 		// a sort key, there is a later nod_field in the item
 		// list that contains the data to send back
 
-		if (IS_INTL_DATA(&item->desc) &&
+		if ((IS_INTL_DATA(&item->desc) || item->desc.isDecFloat()) &&
 			(ULONG)(IPTR) item->desc.dsc_address < m_map->keyLength)
 		{
 			continue;