0001-Don-t-truncate-integer-part-in-to_char-for-FM99.patch

From d0264d8fe8179716bfd58e12201e456387ca5469 Mon Sep 17 00:00:00 2001
From: Marti Raudsepp <marti@juffo.org>
Date: Wed, 7 Sep 2011 20:12:58 +0300
Subject: [PATCH] Don't truncate integer part in to_char for 'FM99.'

When the numeric to_char format used fillmode (FM), didn't contain 0s
and had a trailing dot, the integer part of the number was truncated in
error.

to_char(10, 'FM99.') used to return '1', now it will return '10'
---
 src/backend/utils/adt/formatting.c    |   29 ++++++++++++++++-------------
 src/test/regress/expected/numeric.out |    6 ++++++
 src/test/regress/sql/numeric.sql      |    2 ++
 3 files changed, 24 insertions(+), 13 deletions(-)

diff --git a/src/backend/utils/adt/formatting.c b/src/backend/utils/adt/formatting.c
index 7efd988..eada4a8 100644
--- a/src/backend/utils/adt/formatting.c
+++ b/src/backend/utils/adt/formatting.c
@@ -979,7 +979,7 @@ static char *fill_str(char *str, int c, int max);
 static FormatNode *NUM_cache(int len, NUMDesc *Num, text *pars_str, bool *shouldFree);
 static char *int_to_roman(int number);
 static void NUM_prepare_locale(NUMProc *Np);
-static char *get_last_relevant_decnum(char *num);
+static char *get_last_relevant_decnum(NUMProc *Np);
 static void NUM_numpart_from_char(NUMProc *Np, int id, int plen);
 static void NUM_numpart_to_char(NUMProc *Np, int id);
 static char *NUM_processor(FormatNode *node, NUMDesc *Num, char *inout, char *number,
@@ -3911,17 +3911,26 @@ NUM_prepare_locale(NUMProc *Np)
  * ----------
  */
 static char *
-get_last_relevant_decnum(char *num)
+get_last_relevant_decnum(NUMProc *Np)
 {
 	char	   *result,
-			   *p = strchr(num, '.');
+			   *p;
 
 #ifdef DEBUG_TO_FROM_CHAR
 	elog(DEBUG_elog_output, "get_last_relevant_decnum()");
 #endif
 
-	if (!p)
-		p = num;
+	if (Np->Num->zero_end > Np->num_pre)
+		/* Keep digits according to '0's in the format */
+		p = Np->number + Np->Num->zero_end - Np->num_pre;
+	else
+	{
+		p = strchr(Np->number, '.');
+
+		if (!p)
+			return NULL;
+	}
+
 	result = p;
 
 	while (*(++p))
@@ -4458,14 +4467,8 @@ NUM_processor(FormatNode *node, NUMDesc *Num, char *inout, char *number,
 	{
 		Np->num_pre = plen;
 
-		if (IS_FILLMODE(Np->Num))
-		{
-			if (IS_DECIMAL(Np->Num))
-				Np->last_relevant = get_last_relevant_decnum(
-															 Np->number +
-									 ((Np->Num->zero_end - Np->num_pre > 0) ?
-									  Np->Num->zero_end - Np->num_pre : 0));
-		}
+		if (IS_FILLMODE(Np->Num) && IS_DECIMAL(Np->Num))
+			Np->last_relevant = get_last_relevant_decnum(Np);
 
 		if (Np->sign_wrote == FALSE && Np->num_pre == 0)
 			++Np->num_count;
diff --git a/src/test/regress/expected/numeric.out b/src/test/regress/expected/numeric.out
index d9927b7..e12ab5b 100644
--- a/src/test/regress/expected/numeric.out
+++ b/src/test/regress/expected/numeric.out
@@ -1154,6 +1154,12 @@ SELECT '' AS to_char_23, to_char(val, '9.999EEEE')				FROM num_data;
             | -2.493e+07
 (10 rows)
 
+SELECT '' AS to_char_24, to_char('100'::numeric, 'FM999.');
+ to_char_24 | to_char 
+------------+---------
+            | 100
+(1 row)
+
 -- TO_NUMBER()
 --
 SELECT '' AS to_number_1,  to_number('-34,338,492', '99G999G999');
diff --git a/src/test/regress/sql/numeric.sql b/src/test/regress/sql/numeric.sql
index a1435ec..d552526 100644
--- a/src/test/regress/sql/numeric.sql
+++ b/src/test/regress/sql/numeric.sql
@@ -764,6 +764,8 @@ SELECT '' AS to_char_21, to_char(val, '999999SG9999999999')			FROM num_data;
 SELECT '' AS to_char_22, to_char(val, 'FM9999999999999999.999999999999999')	FROM num_data;
 SELECT '' AS to_char_23, to_char(val, '9.999EEEE')				FROM num_data;
 
+SELECT '' AS to_char_24, to_char('100'::numeric, 'FM999.');
+
 -- TO_NUMBER()
 --
 SELECT '' AS to_number_1,  to_number('-34,338,492', '99G999G999');
-- 
1.7.6.1