Created attachment 340917 [details]
example files to reproduce problem

When I have one doxygen project documenting some python code and generate a tagfile for it and another doxygen project that tries to reference a file of the python code via the tagfile, then a wrong link is created in the HTML output of the latter project.

In the attached small example, foo.py is documented in foo_html/foo_8py.html.
However, the link in main_html/index.html points to foo__8py.html, that is, there is an additional underscore.

The .tag file has
<tagfile>
  <compound kind="file">
    <name>foo.py</name>
    <path>/home/stefan/tmp/doxygenpythonbug/</path>
    <filename>foo_8py</filename>
...

On our side, the Python code is the only one that creates compounds with kind "file" in tag files. Somewhere, I would guess, an underscore gets "escaped" too often.

To reproduce, first run doxygen on Doxygen_foo and then on Doxygen_main and open main_html/index.html.