5 Replies Latest reply: Sep 19, 2014 3:18 AM by ToM_1st RSS

    Duplicate entries in the Fields array

    ToM_1st Community Member
    ToM_1st Aug 25, 2014 6:44 AM

      I came across a (strange) pdf and after an analysis it turned out that some of the fields occur multiple times in the Fields array.

      Now when looking up the spec it states:

      "An array of references to the document’s root fields (those with no ancestors in the field hierarchy)."

       

      Is that a violation of the spec (although it doesn't state that explicitly)?

      So how to deal with this kind of PDFs?

        • 1. Re: Duplicate entries in the Fields array
          lrosenth Adobe Employee
          lrosenth Aug 25, 2014 7:38 AM (in response to ToM_1st)

          Meaning the same object reference is listed in the Fields array?    Eg. ?

          • 2. Re: Duplicate entries in the Fields array
            ToM_1st Community Member
            ToM_1st Aug 25, 2014 9:38 AM (in response to lrosenth)

            Yes.

            The fields array looks like that (I shortened it with ...):

             

            749 0 obj

            <</Fields[19 0 R 119 0 R 120 0 R 121 0 R 122 0 R 122 0 R 122 0 R 122 0 R 122 0 R 128 0 R 129 0 R 129 0 R 132 0 R 133 0 R 133 0 R 136 0 R 137 0 R 138 0 R 139 0 R 139 0 R ...]

             

            As you can see the 122 0 R is in there 5x.

            Now I also saw that in the Annots array are also duplicate values:

             

            /Annots[119 0 R 120 0 R 121 0 R 123 0 R 123 0 R 124 0 R 123 0 R 124 0 R 125 0 R 123 0 R 124 0 R 125 0 R 126 0 R 123 0 R 124 0 R 125 0 R 126 0 R 127 0 R 128 0 R ...]

            • 3. Re: Duplicate entries in the Fields array
              lrosenth Adobe Employee
              lrosenth Aug 25, 2014 9:49 AM (in response to ToM_1st)

              Sounds like someone copied some fields and wanted them all to be the same.  eird but I don't see any reason that it's illegal.

              • 4. Re: Duplicate entries in the Fields array
                ToM_1st Community Member
                ToM_1st Aug 26, 2014 1:39 AM (in response to lrosenth)

                Probably not illegal since the spec doesn't say "An array of unique references to the document’s root..." however not everything which isn't explicitly mentioned makes sense or is recommendable. So from my perspective its more on the illegal, than in the 'spirit of the spec' side

                • 5. Re: Duplicate entries in the Fields array
                  ToM_1st Community Member
                  ToM_1st Sep 19, 2014 3:18 AM (in response to lrosenth)

                  A follow up to the discussion: I opened the document in the Life Cycle Designer and it showed me an error (as I would have expected it from acrobat).

                   

                  The explanaination was that a (checked) radiobutton was referenced several times (due to the above problem). And that is definetly a violation of the spec - you can't have several checked radiobuttons in a group - and that is the reason why it should be illegal to have duplicate entries in the /Field or /Annots array (in my opinion).

                   

                  Interesting to know that Lifecycle Designer seems "better" in this way than acrobat - since acrobat didn't complain and LifeCycle Designer showed the correct warning in the first place.