Steps to reproduce: 1. Open composer 2. Type in some text. 3. Select all and change the font size to large (Format->Size->Large) 4. Insert an HR (Insert->Horizontal Line) 5. Type some more text after the HR. What happens is the font size after the horizontal rule has been changed back to the default. The HR should either be inserted in the font tag, or the font styles should be set back after inserting the HR.
Michael: HTML 4 dtd says HR is a block anyway : <!ENTITY % block "P | %heading; | %list; | %preformatted; | DL | DIV | NOSCRIPT | BLOCKQUOTE | FORM | HR | TABLE | FIELDSET | ADDRESS"> so inserting an HR should break the current block. I agree it should recreate the styles, just like when you create a new P after a P hitting twice the return key.
Can you reproduce with SeaMonkey v1.1.9 ?
WFM here, text after hr is large size User agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:16.0) Gecko/16.0 Firefox/16.0 SeaMonkey/2.13a1 Build identifier: 20120712003002