Created attachment 256863 [details]
dox.tar.gz

The \image tag results in a copy from the input directory to the documentation directory. However, it seems that the copy does not check for an existing file in the documentation directory - if a symlink exists there, it looks like the copy follows the symlink (rather than replacing it) and can get confused.

For example, consider the following input (also in the attachment):

doxygen config, 'dox', the output of 'doxygen -s -g dox' with the following changes:
INPUT                  = inputs
FILE_PATTERNS          = *.c
IMAGE_PATH             = inputs
GENERATE_LATEX         = NO

inputs/test.c containing
/** \file test.c
    \image html foo.png
 */

inputs/foo.png is some image.

Now let's put a symlink (back to the original file) in the HTML output directory:
rm -rf html; mkdir html; ln -sf ../inputs/foo.png html

Then run doxygen: 'doxygen dox' and finally look at the resulting images with 'ls -l */foo.png':
lrwxrwxrwx. 1 ben users 17 Oct  9 17:10 html/foo.png -> ../inputs/foo.png
-rw-r--r--. 1 ben users  0 Oct  9 17:10 inputs/foo.png

Note that the original file, inputs/foo.png, is now 0 bytes. My guess is this is because doxygen followed the symlink and so tried to overwrite the file with itself. Seems like a simple fix would be to simply check if a file exists at the destination before doing the copy, and if it does, remove it.