Strange behaviour of ebook-meta on PDF files

[pauloney]

I tried using "ebook-meta" to change the value of metadata entrie in PDF eBook fles and met some strange behaviour that I could not comprehend from the logic pioint of view.
All the example below we produce a sample file with xelatex.

1- Touching the file with "ebook-meta" changes the value of the
"Producer" from xdvipdfmx to XeTeX.

------
xelatex hello.tex

pdfinfo evince Acrobat Chrome
-------------------------------------------------
Creator: XeTeX XeTeX XeTeX XeTeX
Producer: xdvipdfmx xdvipdfmx xdvipdfmx xdvipdfmx

ebook-meta -t 'This is a title' hello.pdf

pdfinfo evince Acrobat Chrome
---------------------------------------------
Creator: XeTeX XeTeX XeTeX XeTeX
Producer: XeTeX XeTeX XeTeX XeTeX

Which is strange, because changing a title should not change
the producer, and the changer should not be XeTeX.
------

2- This command changes TWO metadata values:

------
xelatex hello.tex

pdfinfo evince Acrobat Chrome
-------------------------------------------------
Creator: XeTeX XeTeX XeTeX XeTeX
Producer: xdvipdfmx xdvipdfmx xdvipdfmx xdvipdfmx

ebook-meta -k 'BinB' hello.pdf

pdfinfo evince Acrobat Chrome
---------------------------------------------
Creator: BinB BinB BinB BinB
Producer: BinB BinB BinB BinB

Which is again strange because -k changes values of BOTH metadata entries.
------


3- In this next example, changing a "tag" makes a change in the "producer"

--------------------------------------
xelatex hello.tex

pdfinfo evince Acrobat Chrome
-------------------------------------------------
Creator: XeTeX XeTeX XeTeX XeTeX
Producer: xdvipdfmx xdvipdfmx xdvipdfmx xdvipdfmx

ebook-meta --tags 'This is a tag' hello.pdf

pdfinfo evince Acrobat Chrome
---------------------------------------------
Creator: XeTeX XeTeX XeTeX XeTeX
Producer: XeTeX XeTeX XeTeX XeTeX


Makes the value of the tag above available under the metadata name
"Keywords" as reported in pdfinfo, evince, Adobe Acrobat and Chrome
and changes the value of "Producer" to be the same of "Creator".


4- And finally the most strange of them all:

--------------------------------------
xelatex hello.tex

pdfinfo evince Acrobat Chrome
-------------------------------------------------
Creator: XeTeX XeTeX XeTeX XeTeX
Producer: xdvipdfmx xdvipdfmx xdvipdfmx xdvipdfmx

ebook-meta -c 'Comment' hello.pdf

Makes the value "Comment" to show up under the metadata "Subject"
under evince, but NOT under pdfinfo, Chrome or Acrobat.

[kovidgoyal]

this will likely be because xelatex is producing pdf with messed up /Info dictionary. Use a pdf from a different source. Or run your pdf through pdf2ps and ps2pdf to fix it.