created an attachment (id=167874)
report

build number:2.6.0.v20100511-0630

steps to reproduce:
1. copy a.jpg to project
2. new a report, insert a text item, html type, input "<img src="a.jpg" height="50"/>"
3. preview in all formats

expected result:
height works but will not affect width

actual result:
only in doc, keep original width.
in other formats, image both width and height are changed.
all output formats should be consistent with the browser's behavior.
fixed the problem.
all formats follow the browser effect, height and width both change.