Fix some whitespace issues in XMLSERIALIZE(... INDENT).

We must drop whitespace while parsing the input, else libxml2
will include "blank" nodes that interfere with the desired
indentation behavior.  The end result is that we didn't indent
nodes separated by whitespace.

Also, it seems that libxml2 may add a trailing newline when working
in DOCUMENT mode.  This is semantically insignificant, so strip it.

This is in the gray area between being a bug fix and a definition
change.  However, the INDENT option is still pretty new (since v16),
so I think we can get away with changing this in stable branches.
Hence, back-patch to v16.

Jim Jones

Discussion: https://postgr.es/m/872865a8-548b-48e1-bfcd-4e38e672c1e4@uni-muenster.de

diff --git a/src/backend/utils/adt/xml.c b/src/backend/utils/adt/xml.c
index 0255349aa43c58e9920bc28cdf0e443099523450..68bbf86cc46a238474de7457b272c38140aae504 100644 (file)
--- a/src/backend/utils/adt/xml.c
+++ b/src/backend/utils/adt/xml.c
@@ -656,8 +656,14 @@ xmltotext_with_options(xmltype *data, XmlOptionType xmloption_arg, bool indent)
        }
 
 #ifdef USE_LIBXML
-       /* Parse the input according to the xmloption */
-       doc = xml_parse(data, xmloption_arg, true, GetDatabaseEncoding(),
+
+       /*
+        * Parse the input according to the xmloption.
+        *
+        * preserve_whitespace is set to false in case we are indenting, otherwise
+        * libxml2 will fail to indent elements that have whitespace between them.
+        */
+       doc = xml_parse(data, xmloption_arg, !indent, GetDatabaseEncoding(),
                                        &parsed_xmloptiontype, &content_nodes,
                                        (Node *) &escontext);
        if (doc == NULL || escontext.error_occurred)
@@ -781,7 +787,22 @@ xmltotext_with_options(xmltype *data, XmlOptionType xmloption_arg, bool indent)
                                                "could not close xmlSaveCtxtPtr");
                }
 
-               result = (text *) xmlBuffer_to_xmltype(buf);
+               /*
+                * xmlDocContentDumpOutput may add a trailing newline, so remove that.
+                */
+               if (xmloption_arg == XMLOPTION_DOCUMENT)
+               {
+                       const char *str = (const char *) xmlBufferContent(buf);
+                       int                     len = xmlBufferLength(buf);
+
+                       while (len > 0 && (str[len - 1] == '\n' ||
+                                                          str[len - 1] == '\r'))
+                               len--;
+
+                       result = cstring_to_text_with_len(str, len);
+               }
+               else
+                       result = (text *) xmlBuffer_to_xmltype(buf);
        }
        PG_CATCH();
        {

diff --git a/src/test/regress/expected/xml.out b/src/test/regress/expected/xml.out
index 15d99185794680b26952f81442a6424d36d905be..894ee6bd2b730b635ed656f5389a10f46f658541 100644 (file)
--- a/src/test/regress/expected/xml.out
+++ b/src/test/regress/expected/xml.out
@@ -485,8 +485,7 @@ 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);
@@ -546,8 +545,7 @@ 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);
@@ -601,8 +599,7 @@ 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);
@@ -620,8 +617,7 @@ 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);
@@ -638,8 +634,7 @@ 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);
@@ -663,6 +658,24 @@ SELECT xmlserialize(CONTENT  '<foo><bar><val x="y">42</val></bar></foo>' AS text
  t
 (1 row)
 
+-- indent xml strings containing blank nodes
+SELECT xmlserialize(DOCUMENT '<foo>   <bar></bar>    </foo>' AS text INDENT);
+ xmlserialize 
+--------------
+ <foo>       +
+   <bar/>    +
+ </foo>
+(1 row)
+
+SELECT xmlserialize(CONTENT  'text node<foo>    <bar></bar>   </foo>' AS text INDENT);
+ xmlserialize 
+--------------
+ text node   +
+ <foo>       +
+   <bar/>    +
+ </foo>
+(1 row)
+
 SELECT xml '<foo>bar</foo>' IS DOCUMENT;
  ?column? 
 ----------

diff --git a/src/test/regress/expected/xml_1.out b/src/test/regress/expected/xml_1.out
index 63b779470ff6dcd09f4f4ac3b0b68da0ee622784..7e9611f1d38861a31e12cf9f287c1968615f6d65 100644 (file)
--- a/src/test/regress/expected/xml_1.out
+++ b/src/test/regress/expected/xml_1.out
@@ -443,6 +443,17 @@ ERROR:  unsupported XML feature
 LINE 1: SELECT xmlserialize(CONTENT  '<foo><bar><val x="y">42</val><...
                                      ^
 DETAIL:  This functionality requires the server to be built with libxml support.
+-- indent xml strings containing blank nodes
+SELECT xmlserialize(DOCUMENT '<foo>   <bar></bar>    </foo>' AS text INDENT);
+ERROR:  unsupported XML feature
+LINE 1: SELECT xmlserialize(DOCUMENT '<foo>   <bar></bar>    </foo>'...
+                                     ^
+DETAIL:  This functionality requires the server to be built with libxml support.
+SELECT xmlserialize(CONTENT  'text node<foo>    <bar></bar>   </foo>' AS text INDENT);
+ERROR:  unsupported XML feature
+LINE 1: SELECT xmlserialize(CONTENT  'text node<foo>    <bar></bar> ...
+                                     ^
+DETAIL:  This functionality requires the server to be built with libxml support.
 SELECT xml '<foo>bar</foo>' IS DOCUMENT;
 ERROR:  unsupported XML feature
 LINE 1: SELECT xml '<foo>bar</foo>' IS DOCUMENT;

diff --git a/src/test/regress/expected/xml_2.out b/src/test/regress/expected/xml_2.out
index 8894f7b4a84f0de8a3153891f42014af1897a8aa..7d5c961e24049cbd841cbf7d16d4c65cb703f2e8 100644 (file)
--- a/src/test/regress/expected/xml_2.out
+++ b/src/test/regress/expected/xml_2.out
@@ -471,8 +471,7 @@ 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);
@@ -532,8 +531,7 @@ 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);
@@ -587,8 +585,7 @@ 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);
@@ -606,8 +603,7 @@ 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);
@@ -624,8 +620,7 @@ 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);
@@ -649,6 +644,24 @@ SELECT xmlserialize(CONTENT  '<foo><bar><val x="y">42</val></bar></foo>' AS text
  t
 (1 row)
 
+-- indent xml strings containing blank nodes
+SELECT xmlserialize(DOCUMENT '<foo>   <bar></bar>    </foo>' AS text INDENT);
+ xmlserialize 
+--------------
+ <foo>       +
+   <bar/>    +
+ </foo>
+(1 row)
+
+SELECT xmlserialize(CONTENT  'text node<foo>    <bar></bar>   </foo>' AS text INDENT);
+ xmlserialize 
+--------------
+ text node   +
+ <foo>       +
+   <bar/>    +
+ </foo>
+(1 row)
+
 SELECT xml '<foo>bar</foo>' IS DOCUMENT;
  ?column? 
 ----------

diff --git a/src/test/regress/sql/xml.sql b/src/test/regress/sql/xml.sql
index a591eea2e5d14dec4acf4501d59ddfd8d6d70b25..0b07075414e806f32bb5735247830f13d26754e6 100644 (file)
--- a/src/test/regress/sql/xml.sql
+++ b/src/test/regress/sql/xml.sql
@@ -168,6 +168,9 @@ SELECT xmlserialize(CONTENT  '<foo><bar></bar></foo>' AS text INDENT);
 -- 'no indent' = not using 'no indent'
 SELECT xmlserialize(DOCUMENT '<foo><bar><val x="y">42</val></bar></foo>' AS text) = xmlserialize(DOCUMENT '<foo><bar><val x="y">42</val></bar></foo>' AS text NO INDENT);
 SELECT xmlserialize(CONTENT  '<foo><bar><val x="y">42</val></bar></foo>' AS text) = xmlserialize(CONTENT '<foo><bar><val x="y">42</val></bar></foo>' AS text NO INDENT);
+-- indent xml strings containing blank nodes
+SELECT xmlserialize(DOCUMENT '<foo>   <bar></bar>    </foo>' AS text INDENT);
+SELECT xmlserialize(CONTENT  'text node<foo>    <bar></bar>   </foo>' AS text INDENT);
 
 SELECT xml '<foo>bar</foo>' IS DOCUMENT;
 SELECT xml '<foo>bar</foo><bar>foo</bar>' IS DOCUMENT;