Problem/Motivation
Following
✨
Export configuration YAML strings as multiline
Fixed
, multiline syntax is used for yml that contains newline characters. This has caused a problem with a certain migration yml that describes doing a find-replace involving newlines. After a few configuration imports and exports, "\n" gets transformed into ''. The configuration for the process plugin starts out like this:
plugin: str_replace
source: post_content
regex: TRUE
search: "/(\r\n)+/"
replace: "\n"
Some time later (apparently after any other configuration is changed), this will get exported using the multiline syntax:
plugin: str_replace
source: post_content
regex: TRUE
search: "/(\r\n)+/"
replace: |
Then some time after that, the config will get exported like this:
plugin: str_replace
source: post_content
regex: TRUE
search: "/(\r\n)+/"
replace: ''
which is very different from what we started with.
Steps to Reproduce
The bug takes two "round trips" of encoding and decoding to reveal itself. Here are some commands that can be run in drush.
drush ev 'print json_encode(\Drupal\Component\Serialization\YamlSymfony::decode(\Drupal\Component\Serialization\YamlSymfony::encode(\Drupal\Component\Serialization\YamlSymfony::decode(\Drupal\Component\Serialization\YamlSymfony::encode(["foo" => "\n"])))))'
Expected output is {"foo":"\n"}
Actual output: {"foo":""}
Compare this to adding bar next to the newline, which works fine.
drush ev 'print json_encode(\Drupal\Component\Serialization\YamlSymfony::decode(\Drupal\Component\Serialization\YamlSymfony::encode(\Drupal\Component\Serialization\YamlSymfony::decode(\Drupal\Component\Serialization\YamlSymfony::encode(["foo" => "bar\n"])))))'
Expected output is {"foo":"bar\n"}
Actual output: {"foo":"bar\n"}
What happens with other strings that are composed only of newlines?
drush ev 'print json_encode(\Drupal\Component\Serialization\YamlSymfony::decode(\Drupal\Component\Serialization\YamlSymfony::encode(\Drupal\Component\Serialization\YamlSymfony::decode(\Drupal\Component\Serialization\YamlSymfony::encode(["foo" => "\n\n"])))))'
Expected output is {"foo":"\n\n"}
Actual output: {"foo":""}
drush ev 'print json_encode(\Drupal\Component\Serialization\YamlSymfony::decode(\Drupal\Component\Serialization\YamlSymfony::encode(\Drupal\Component\Serialization\YamlSymfony::decode(\Drupal\Component\Serialization\YamlSymfony::encode(["foo" => "\n\n\n"])))))'
Expected output is {"foo":"\n\n\n"}
Actual output: {"foo":"\n"}
drush ev 'print json_encode(\Drupal\Component\Serialization\YamlSymfony::decode(\Drupal\Component\Serialization\YamlSymfony::encode(\Drupal\Component\Serialization\YamlSymfony::decode(\Drupal\Component\Serialization\YamlSymfony::encode(["foo" => "\n\n\n\n"])))))'
Expected output is {"foo":"\n\n\n\n"}
Actual output: {"foo":"\n\n"}
Proposed resolution
TBD
Remaining tasks
TBD
User interface changes
None
API changes
TBD
Data model changes
TBD
Release notes snippet
TBD