Entering text like this issue where lines are created by merely entering a new-line character - like so -
causes the rendered text to display a line-break.

This problem also affects JIRA 3.7 (and earlier?).

This violates standard wiki markup behaviour as known in all major wikis I know of (wikipedia, c2, ...).
Wiki markups and others like HTML, Tex/LaTex, etc. follow the principle of What you get is what you mean
(WYGIWYM), not WYSIWYG. This usually means:

• Empty line creates new paragraph
• Line-break is explicit
• New line does not create a line-break,

In addition, Confluence and JIRA have line-break markup, vis.

\\

. This markup
is either superfluous (as the current rendering shows) or its intention has been corrupted as described
in this bug.

I dislike the fact that I am forced to write sentences spreading for ever across the screen in order to avoid funny formatting of my text (as I am doing right now). This also violates the long accepted advice to reduce the width of printed text. However, reducing the browser to a width that is acceptable for editing is most often not acceptable when viewing JIRA issues in tabular form. Switching widths depending on context is not an acceptable workaround.

Summary: Change rendering behaviour to fall in line with other wiki editors.