fix: set_font() early-return skips current_font restore when font state diverges#1872
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andersonhc merged 2 commits intoJun 26, 2026
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When a fallback font is used during rendering, the internal `current_font`
can diverge from `font_family`: `font_family` stays as the primary font
name while `current_font` is updated to the fallback font object (fpdf.py
line ~4167). After rendering, `set_font('primary')` hits the early-return
guard that checks `font_family == family`, finds a match, and returns
without restoring `current_font` to the primary font object.
Add `current_font.fontkey == fontkey` to the early-return condition so
that a diverged state (font_family matches but current_font does not)
is always corrected by proceeding through the full `set_font()` logic.
Moves `fontkey = family + style` above the early-return check to avoid
computing it twice.
Fixes py-pdf#1488
andersonhc
requested changes
Jun 25, 2026
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Added the changelog entry in Local verification:
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Collaborator
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@allcontributors please add @gaoflow for code |
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I've put up a pull request to add @gaoflow! 🎉 |
Collaborator
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Merged. Thank you @gaoflow |
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Problem
set_font()has an early-return guard that fires whenfont_family,font_style, andfont_size_ptall match the requested values. However it does not check whethercurrent_fontis consistent with those high-level attributes.When a fallback font is rendered (see line ~4167 in
fpdf.py), the code updatesself.current_fontto the fallback font object while leavingself.font_familypointing to the primary font. After rendering, callingset_font('primary')findsfont_family == 'primary'(match),font_style == ''(match), andfont_size_pt(match), so it returns early without restoringcurrent_fontback to the primary font object.This is the root cause of #1488: subsequent PDF rendering uses the stale fallback
current_font.Fix
Add
self.current_font.fontkey == fontkeyto the early-return condition. Whencurrent_fonthas diverged fromfont_family(inconsistent state), the guard no longer fires andset_font()proceeds through its full logic to select the correct font.As a minor cleanup,
fontkey = family + styleis now computed once before the early-return check (instead of again immediately after).Test
Added
test_set_font_restores_current_font_after_state_divergenceintest/fonts/test_set_font.pythat:font_family = 'helvetica'whilecurrent_font = times_fontset_font('Helvetica')and assertscurrent_font.fontkey == 'helvetica'The test fails on the old code and passes with this fix.
This pull request was prepared with the assistance of AI, under my direction and review.