Bug 421445

Created attachment 128412 [details]
Screenshot of incorrectly highlighted opening double quote

SUMMARY

When double quoting a string in a PostgreSQL statement such as when setting an output name in a select statement, the opening double quote is highlighted as a comment instead of as an identifier.


STEPS TO REPRODUCE

1. Create a new document in Kate
2. Set syntax highlighting language to "SQL (PostgreSQL)"
3. Write a statement including a double quote, for example

        select 'foo' "bar";


OBSERVED RESULT

The opening double quote is highlighted as a comment, the identifier and the closing double quote as an identifier (see attachment).


EXPECTED RESULT

The quoted string is highlighted as an identifier, both quotes included.


SOFTWARE/OS VERSIONS

Ubuntu 19.10
Kate 19.04.3
KDE Frameworks 5.62.0
Qt 5.12.4 (built against 5.12.4)


ADDITIONAL INFORMATION

The same error affects Pandoc syntax highlighting, which uses Skylighting, which uses the KDE syntax definition files.

John MacFarlane, the creator of Skylighting and Pandoc, pointed me to this line in the syntax file, which seems to be the culprit:

    <DetectChar attribute="Comment" context="Identifier" char="&quot;"/>

Phabricator link: https://phabricator.kde.org/source/syntax-highlighting/browse/master/data/syntax/sql-postgresql.xml$1010

Looking further to when this was introduced, I found this commit back when syntax highlighting was in Kate: https://invent.kde.org/kde/kate/-/commit/2e55bd0ca7deaaffe5546f04e2925112cca2a9a6#5d04d3f12b2774e3618e339c318f3154ac45df03

It changes line 749 from

    <DetectChar attribute="9" context="5" char="&quot;"/>

to the line shown above (line 750 after commit diff):

    <DetectChar attribute="Comment" context="Identifier" char="&quot;"/>

but attribute="9" corresponds to "Identifier"; "Comment" would be "8", as can be seen by inspecting the surrounding lines and the <itemDatas> array.