REXML fails to conform to the XPath spec §5.7

[ser]

From the XPath spec:

5.7 Text Nodes

Character data is grouped into text nodes. As much character data as possible is grouped into each text node: a text node never has an immediately following or preceding sibling that is a text node. The string-value of a text node is the character data. A text node always has at least one character of data.

Need to see if the XML spec says anything about this, but this sort of behavior makes sense; when you add text to a node, if the preceding sibling is a text node, they should be joined.

[ser]

This actually already works properly.