Re: [PATCH] Add pretty-printed XML output option

Something is misbehaving.

Using the latest HEAD, and before applying the v6 patch, 'make check'
is working OK.

But after applying the v6 patch, some XML regression tests are failing
because the DETAIL part of the message indicating the wrong syntax
position is not getting displayed. Not only for your new tests -- but
for other XML tests too.

My ./configure looks like this:
./configure --prefix=/usr/local/pg_oss --with-libxml --enable-debug
--enable-cassert --enable-tap-tests  CFLAGS="-ggdb -O0 -g3
-fno-omit-frame-pointer"

resulting in:
checking whether to build with XML support... yes
checking for libxml-2.0 >= 2.6.23... yes

~

e.g.(these are a sample of errors)

xml                          ... FAILED     2561 ms

@@ -344,8 +326,6 @@
 <twoerrors>&idontexist;</unbalanced>
                        ^
 line 1: Opening and ending tag mismatch: twoerrors line 1 and unbalanced
-<twoerrors>&idontexist;</unbalanced>
-                                    ^
 SELECT xmlparse(document '<nosuchprefix:tag/>');
       xmlparse
 ---------------------
@@ -1696,14 +1676,8 @@
 SELECT xmlformat('');
 ERROR:  invalid XML document
 DETAIL:  line 1: switching encoding : no input
-
-^
 line 1: Document is empty
-
-^
 -- XML format: invalid string (whitespaces)
 SELECT xmlformat('   ');
 ERROR:  invalid XML document
 DETAIL:  line 1: Start tag expected, '<' not found
-
-   ^

~~

Separately (but maybe it's related?), the CF-bot test also reported a
failure [1] with strange error detail differences.

diff -U3 /tmp/cirrus-ci-build/src/test/regress/expected/xml.out
/tmp/cirrus-ci-build/build/testrun/regress/regress/results/xml.out
--- /tmp/cirrus-ci-build/src/test/regress/expected/xml.out 2023-02-12
09:02:57.077569000 +0000
+++ /tmp/cirrus-ci-build/build/testrun/regress/regress/results/xml.out
2023-02-12 09:05:45.148100000 +0000
@@ -1695,10 +1695,7 @@
 -- XML format: empty string
 SELECT xmlformat('');
 ERROR:  invalid XML document
-DETAIL:  line 1: switching encoding : no input
-
-^
-line 1: Document is empty
+DETAIL:  line 1: Document is empty

 ^
 -- XML format: invalid string (whitespaces)

------
[1] https://api.cirrus-ci.com/v1/artifact/task/4802219812323328/testrun/build/testrun/regress/regress/regression.diffs

Kind Regards,
Peter Smith.
Fujitsu Australia