Block attribute paragraph leaves leading newline in block (Pandoc spec violation) #756

New Issue

claunia · 2026-01-29T14:44:50Z

claunia commented

2026-01-29 14:44:50 +00:00

Originally created by @Asttear on GitHub (Sep 27, 2025).

Bug Description

When using GenericAttributesParser, if an attribute block (e.g., {.center}) appears on a line by itself immediately before a block element (such as a paragraph), the resulting block element includes a leading newline (\n) in its content.

Expected Behavior

According to the Pandoc Markdown specification:

Attributes that occur immediately before a block element, on a line by themselves, affect that element.

The attribute block should be associated with the following block element, but the content of the block element should not include an extra leading newline.

How to Reproduce

Steps:

Create a markdown file containing:
```
{.center}
A paragraph
```
Parse this with Markdig (with GenericAttributes enabled)
Observe that the paragraph block contains a leading \n in its content.

Actual Behavior

The paragraph block has a leading newline before the text, which is preserved in the rendered HTML or output.

Expected Output

The paragraph should have the attribute applied, but its content should be:

A paragraph

without any leading newline.

Reference

Pandoc Markdown spec: https://pandoc.org/MANUAL.html#extension-attributes

Additional Context

This may be due to how the parser transitions from the attribute block to the following block, and does not trim the whitespace. This leads to non-compliance with Markdown attribute extension behavior as described in Pandoc.

Please consider aligning this behavior with the Pandoc spec by trimming/removing the leading newline when attaching attributes from an attribute-only paragraph to the next block.

Originally created by @Asttear on GitHub (Sep 27, 2025). ## Bug Description When using GenericAttributesParser, if an attribute block (e.g., `{.center}`) appears on a line by itself immediately before a block element (such as a paragraph), the resulting block element includes a leading newline (`\n`) in its content. ## Expected Behavior According to the Pandoc Markdown specification: > Attributes that occur immediately before a block element, on a line by themselves, affect that element. The attribute block should be associated with the following block element, but the content of the block element should not include an extra leading newline. ## How to Reproduce Steps: 1. Create a markdown file containing: ``` {.center} A paragraph ``` 2. Parse this with Markdig (with GenericAttributes enabled) 3. Observe that the paragraph block contains a leading `\n` in its content. ## Actual Behavior The paragraph block has a leading newline before the text, which is preserved in the rendered HTML or output. ## Expected Output The paragraph should have the attribute applied, but its content should be: ``` A paragraph ``` without any leading newline. ## Reference Pandoc Markdown spec: https://pandoc.org/MANUAL.html#extension-attributes ## Additional Context This may be due to how the parser transitions from the attribute block to the following block, and does not trim the whitespace. This leads to non-compliance with Markdown attribute extension behavior as described in Pandoc. Please consider aligning this behavior with the Pandoc spec by trimming/removing the leading newline when attaching attributes from an attribute-only paragraph to the next block.

claunia closed this issue

2026-01-29 14:44:51 +00:00

Sign in to join this conversation.

Branches Tags

1 Participants

Notifications

Due Date

No due date set.

Dependencies

No dependencies set.

Reference: starred/markdig#756