From aa5eafb319da04d2e67a1540af0d088af6d82edb Mon Sep 17 00:00:00 2001
From: Jim Jones <jim.jones@uni-muenster.de>
Date: Mon, 24 Apr 2023 10:02:32 +0200
Subject: [PATCH v1] Remove trailing newlines from xmlserialize indent output

This removes the trailing newlines added to xmlserialize indent
output from xml strings of type DOCUMENT.

Reported by: Pavel Stehule
Discussion : https://www.postgresql.org/message-id/CAFj8pRCNTi2yHBXcdYf-cYZ63R8Laf9L49Q_uxt%2BA5WXKPPhxg%40mail.gmail.com
---
 src/backend/utils/adt/xml.c         | 20 +++++++++++++++++++-
 src/test/regress/expected/xml.out   | 15 +++++----------
 src/test/regress/expected/xml_2.out | 15 +++++----------
 3 files changed, 29 insertions(+), 21 deletions(-)

diff --git a/src/backend/utils/adt/xml.c b/src/backend/utils/adt/xml.c
index 15adbd6a01..404a2f455d 100644
--- a/src/backend/utils/adt/xml.c
+++ b/src/backend/utils/adt/xml.c
@@ -771,7 +771,25 @@ xmltotext_with_options(xmltype *data, XmlOptionType xmloption_arg, bool indent)
 						"could not close xmlSaveCtxtPtr");
 		}
 
-		result = (text *) xmlBuffer_to_xmltype(buf);
+		/*
+		* This is necessary to remove the trailing newline created
+		* by xmlSaveDoc - it only affects DOCUMENT xml strings.
+		* The fragments of CONTENT strings are stored into the
+		* xmlBufferPtr using xmlSaveTree, which does not add a
+		* trailing newline.
+		*/
+		if(xmloption_arg != XMLOPTION_DOCUMENT)
+			result = (text *) xmlBuffer_to_xmltype(buf);
+		else
+		{
+			int	len = xmlBufferLength(buf);
+			const char *xmloutput = (const char *) xmlBufferContent(buf);
+
+			while (len > 0 && xmloutput[len - 1] == '\n')
+				len--;
+
+			result = cstring_to_text_with_len(xmloutput, len);
+		}
 	}
 	PG_CATCH();
 	{
diff --git a/src/test/regress/expected/xml.out b/src/test/regress/expected/xml.out
index 398345ca67..b689f86fe6 100644
--- a/src/test/regress/expected/xml.out
+++ b/src/test/regress/expected/xml.out
@@ -494,8 +494,7 @@ SELECT xmlserialize(DOCUMENT '<foo><bar><val x="y">42</val></bar></foo>' AS text
    <bar>                +
      <val x="y">42</val>+
    </bar>               +
- </foo>                 +
- 
+ </foo>
 (1 row)
 
 SELECT xmlserialize(CONTENT  '<foo><bar><val x="y">42</val></bar></foo>' AS text INDENT);
@@ -555,8 +554,7 @@ SELECT xmlserialize(DOCUMENT '<foo><bar><val x="y">42</val><val x="y">text node<
      <val x="y">42</val>                    +
      <val x="y">text node<val>73</val></val>+
    </bar>                                   +
- </foo>                                     +
- 
+ </foo>
 (1 row)
 
 SELECT xmlserialize(CONTENT  '<foo><bar><val x="y">42</val><val x="y">text node<val>73</val></val></bar></foo>' AS text INDENT);
@@ -610,8 +608,7 @@ SELECT xmlserialize(DOCUMENT '<?xml version="1.0" encoding="UTF-8"?><foo><bar><v
    <bar>                               +
      <val>73</val>                     +
    </bar>                              +
- </foo>                                +
- 
+ </foo>
 (1 row)
 
 SELECT xmlserialize(CONTENT  '<?xml version="1.0" encoding="UTF-8"?><foo><bar><val>73</val></bar></foo>' AS text INDENT);
@@ -629,8 +626,7 @@ SELECT xmlserialize(DOCUMENT '<!DOCTYPE a><a/>' AS text INDENT);
  xmlserialize 
 --------------
  <!DOCTYPE a>+
- <a/>        +
- 
+ <a/>
 (1 row)
 
 SELECT xmlserialize(CONTENT  '<!DOCTYPE a><a/>' AS text INDENT);
@@ -647,8 +643,7 @@ SELECT xmlserialize(DOCUMENT '<foo><bar></bar></foo>' AS text INDENT);
 --------------
  <foo>       +
    <bar/>    +
- </foo>      +
- 
+ </foo>
 (1 row)
 
 SELECT xmlserialize(CONTENT  '<foo><bar></bar></foo>' AS text INDENT);
diff --git a/src/test/regress/expected/xml_2.out b/src/test/regress/expected/xml_2.out
index 43c2558352..a2eeff8369 100644
--- a/src/test/regress/expected/xml_2.out
+++ b/src/test/regress/expected/xml_2.out
@@ -474,8 +474,7 @@ SELECT xmlserialize(DOCUMENT '<foo><bar><val x="y">42</val></bar></foo>' AS text
    <bar>                +
      <val x="y">42</val>+
    </bar>               +
- </foo>                 +
- 
+ </foo>
 (1 row)
 
 SELECT xmlserialize(CONTENT  '<foo><bar><val x="y">42</val></bar></foo>' AS text INDENT);
@@ -535,8 +534,7 @@ SELECT xmlserialize(DOCUMENT '<foo><bar><val x="y">42</val><val x="y">text node<
      <val x="y">42</val>                    +
      <val x="y">text node<val>73</val></val>+
    </bar>                                   +
- </foo>                                     +
- 
+ </foo>
 (1 row)
 
 SELECT xmlserialize(CONTENT  '<foo><bar><val x="y">42</val><val x="y">text node<val>73</val></val></bar></foo>' AS text INDENT);
@@ -590,8 +588,7 @@ SELECT xmlserialize(DOCUMENT '<?xml version="1.0" encoding="UTF-8"?><foo><bar><v
    <bar>                               +
      <val>73</val>                     +
    </bar>                              +
- </foo>                                +
- 
+ </foo>
 (1 row)
 
 SELECT xmlserialize(CONTENT  '<?xml version="1.0" encoding="UTF-8"?><foo><bar><val>73</val></bar></foo>' AS text INDENT);
@@ -609,8 +606,7 @@ SELECT xmlserialize(DOCUMENT '<!DOCTYPE a><a/>' AS text INDENT);
  xmlserialize 
 --------------
  <!DOCTYPE a>+
- <a/>        +
- 
+ <a/>
 (1 row)
 
 SELECT xmlserialize(CONTENT  '<!DOCTYPE a><a/>' AS text INDENT);
@@ -627,8 +623,7 @@ SELECT xmlserialize(DOCUMENT '<foo><bar></bar></foo>' AS text INDENT);
 --------------
  <foo>       +
    <bar/>    +
- </foo>      +
- 
+ </foo>
 (1 row)
 
 SELECT xmlserialize(CONTENT  '<foo><bar></bar></foo>' AS text INDENT);
-- 
2.25.1