With SOURCE_DATE_EPOCH set, the document id came from the project's uuid
and a hash of the .qet file. A project generated again from the same
data has new uuids, so its PDF differed in the id alone (XMP DocumentID
and trailer /ID, 120 bytes) although every page was the same.
Qt now writes a fixed placeholder id, and once the file is written the
placeholder is replaced with an id derived from the bytes of the PDF:
the same pages give the same id. Same length, so no offset changes.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Two exports of one project differed in the creation and modification
dates (the time of the export, in local time) and in the document id
(random). With SOURCE_DATE_EPOCH set (reproducible-builds.org),
--export-pdf now uses the time it names, in UTC, and a document id
derived from the project: version 5 of the project uuid with the
SHA-256 of the project file, so it is the same for the same file and
changes when the file does. Qt has no setter for the dates, so
PdfLinks::setDocumentDate() rewrites them in the document information
and the XMP metadata after the file is written, fixing the XMP /Length
and shifting the xref table. Without the variable nothing changes.
Only --export-pdf reads it; the print window's PDF export does not, as
a person exporting by hand wants the real date.
qet_export (misc/qet-mcp) gains "reproducible" and "source_date_epoch".
It reports whether the build honoured the variable, since an older one
ignores it.
tst_pdfreproducible exports examples/741.qet four times and requires
identical bytes and the epoch's date; it fails with either this change
or the hash seed fix reverted. Projects with cross-reference links also
need their links in a fixed order, which is a separate fix.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Qt 6 declares the PDF/X namespace (pdfxid) in the XMP metadata of every
PDF it writes, even when the file is not PDF/X. Adobe Acrobat then draws
small text too bold at some zoom levels. Qt only needs the declaration
for PDF/X-4 output, which QElectroTech never asks for.
Blank the declaration out after export, in place with spaces so no
offsets move, in both the export window and the --export-pdf path.
Diagnosis and the Acrobat testing by Alf, bugtracker #340.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01G2d2Zi8BfrYRPX88zhaoFG
Move the PDF cross-reference hyperlink logic out of ProjectPrintWindow
into a standalone translation unit so it can be reused (the CLI PDF
export will call it next):
- injectCrossRefLinks(): emits the URI link annotations for a diagram's
cross-references and folio reports. The scene-to-page mapping is passed
in as a PageGeometry (transform + devToPdf + source-rect lookup) so each
caller supplies its own correct geometry, rather than the helper assuming
a QPrinter.
- convertUriToGoTo(): the PDF post-processor, moved verbatim.
ProjectPrintWindow stays a pure caller: it builds its PageGeometry from the
printer page layout exactly as before and calls the helper. No behavioural
change to GUI PDF export; no class-structure changes.
Per review guidance on #483.
ispyisail