Re: [PATCH] [mom]: Simplify `pdfhref` calls.

On Friday, 16 January 2026 04:11:42 GMT G. Branden Robinson wrote:
> Hi Peter & Deri,
> 
> I noticed that the `-E` argument to a `.pdfhref L` call doesn't seem to
> do anything.  I compared before-and-after, and while the PDF checksums
> change, the file sizes do not.  I assume there is a shifty data
> structure (like a hash table) or an embedded date stamp in the PDF that
> changes.  I'd have more to report, but _pdfmom_ doesn't support groff's
> `-Z` option.
> 
> Hyperlinks of various types, both internal (whether from tables of
> contents or within body text) and external still work fine, and appear
> to have correct link text.
> 
> Ok to push?
> 
> Regards,
> Branden

Hi Branden,

The -E flag is only documented to be used with .pdfhref M, so you are correct.

Pdfmom does honour both -z (useful for examining forward references) and -Z.

./test-pdfmom -z ../contrib/mom/examples/mom-pdf.mom 
.ds pdf:bm9.tag external
.ds pdf:bm9.val 3.4. Creating external links
.ds flex-space:2@0               126u
.ds pdf:bm10.tag colour
.ds pdf:bm10.val 3.5. Assigning a colour to links
.ds pdf:bm11.tag outline
.ds pdf:bm11.val 4. The PDF Outline
.ds pdf:bm12.tag open-close
.ds pdf:bm12.val 4.1. Opening and closing levels
.ds flex-space:3@0               0u
.ds pdf:bm13.tag disabling
.ds pdf:bm13.val 4.2. Suspending/disabling collection of outline entries
.ds pdf:bm14.tag pdf:title
.ds pdf:bm14.val 4.3. The PDF window title
.ds pdf:bm15.tag toc
.ds pdf:bm15.val 5. Tables of Contents
.ds pdf:bm16.tag toc:gen
.ds pdf:bm16.val 5.1. Generating a Table of Contents
.ds pdf:bm17.tag toc:pos
.ds pdf:bm17.val 5.2. Positioning the Table of Contents
.ds flex-space:4@0               0u
[...]

./test-pdfmom -Z ../contrib/mom/examples/mom-pdf.mom 
x T pdf
x res 72000 1 1
x init
p1
V12000
H72000
x font 5 TR
f5
s10000
md
DFd
V12000
H72000
x X ps: exec 0 setlinejoin
V12000
H72000
x X ps: exec 0 setlinecap
wh2500
V12000
H74500
[...]

"test-pdfmom" is the same as test-groff but the last line is changed to call 
pdfmom rather than groff. I have a vague recollection of someone suggesting we 
use a variable GROFF_BIN in test-groff to select which executable we want to 
run in the test harness. (I may have dreamt this!).

Cheers 

Deri