Fix unexpected error when saving zero dimension images by radarhere · Pull Request #9391 · python-pillow/Pillow

radarhere · 2026-01-12T21:26:21Z

#9389 has pointed out that

from PIL import Image
img = Image.new('RGB', (0, 50))
img.save('test.gif')

raises

Traceback (most recent call last):
  File "demo.py", line 3, in <module>
    img.save('test.gif')
  File "PIL/Image.py", line 2592, in save
    save_handler(self, fp, filename)
  File "PIL/GifImagePlugin.py", line 808, in _save
    _write_single_frame(im, fp, palette)
  File "PIL/GifImagePlugin.py", line 625, in _write_single_frame
    im_out = _normalize_palette(im_out, palette, im.encoderinfo)
  File "PIL/GifImagePlugin.py", line 599, in _normalize_palette
    optimized_palette_colors = _get_optimize(im, info)
  File "PIL/GifImagePlugin.py", line 959, in _get_optimize
    if optimise or max(used_palette_colors) >= len(used_palette_colors):
ValueError: max() arg is an empty sequence

There is also an unexpected error for SPIDER images.

from PIL import Image
img = Image.new('RGB', (0, 50))
img.save('test', 'SPIDER')

raises

Traceback (most recent call last):
  File "demo.py", line 3, in <module>
    im.save('out', 'SPIDER')
  File "PIL/Image.py", line 2592, in save
    save_handler(self, fp, filename)
  File "PIL/SpiderImagePlugin.py", line 296, in _save_spider
    _save(im, fp, filename)
  File "PIL/SpiderImagePlugin.py", line 279, in _save
    hdr = makeSpiderHeader(im)
  File "PIL/SpiderImagePlugin.py", line 248, in makeSpiderHeader
    labrec = int(1024 / lenbyt)
ZeroDivisionError: division by zero

This fixes thse unexpected errors, instead raising

Traceback (most recent call last):
  File "demo.py", line 3, in <module>
    img.save('test.gif')
  File "PIL/Image.py", line 2592, in save
    save_handler(self, fp, filename)
  File "PIL/GifImagePlugin.py", line 808, in _save
    _write_single_frame(im, fp, palette)
  File "PIL/GifImagePlugin.py", line 637, in _write_single_frame
    ImageFile._save(
  File "PIL/ImageFile.py", line 662, in _save
    _encode_tile(im, fp, tile, bufsize, fh)
  File "PIL/ImageFile.py", line 682, in _encode_tile
    encoder.setimage(im.im, extents)
SystemError: tile cannot extend outside image

There is also an unexpected error for PCX images.

from PIL import Image
img = Image.new('RGB', (0, 50))
img.save('test.pcx')

raises

Traceback (most recent call last):
  File "demo.py", line 15, in <module>
    img.save('test.pcx')
  File "PIL/Image.py", line 2592, in save
    save_handler(self, fp, filename)
  File "PIL/PcxImagePlugin.py", line 185, in _save
    + o16(im.size[0] - 1)
  File "PIL/_binary.py", line 100, in o16le
    return pack("<H", i)
struct.error: ushort format requires 0 <= number <= (32767 * 2 + 1)

This adds a new error, similar to JPEG

Traceback (most recent call last):
  File "demo.py", line 15, in <module>
    img.save('test.pcx')
  File "PIL/Image.py", line 2592, in save
    save_handler(self, fp, filename)
  File "PIL/PcxImagePlugin.py", line 151, in _save
    raise ValueError(msg)
ValueError: Cannot write empty image as PCX

This PR contains the following updates: | Package | Change | [Age](https://docs.renovatebot.com/merge-confidence/) | [Confidence](https://docs.renovatebot.com/merge-confidence/) | |---|---|---|---| | [pillow](https://github.com/python-pillow/Pillow) ([changelog](https://github.com/python-pillow/Pillow/releases)) | `<12.1.2,>=12.1.1` → `<12.2.1,>=12.2.0` | ![age](https://developer.mend.io/api/mc/badges/age/pypi/pillow/12.2.0?slim=true) | ![confidence](https://developer.mend.io/api/mc/badges/confidence/pypi/pillow/12.1.1/12.2.0?slim=true) | --- ### Release Notes <details> <summary>python-pillow/Pillow (pillow)</summary> ### [`v12.2.0`](https://github.com/python-pillow/Pillow/releases/tag/12.2.0) [Compare Source](python-pillow/Pillow@12.1.1...12.2.0) <https://pillow.readthedocs.io/en/stable/releasenotes/12.2.0.html> #### Documentation - Update 12.2.0 release notes [#9522](python-pillow/Pillow#9522) \[[@hugovk](https://github.com/hugovk)] - Add loader plugins: AMOS abk, Atari Degas, 40+ more obscure formats via Netpbm [#9482](python-pillow/Pillow#9482) \[[@bitplane](https://github.com/bitplane)] - Update Python versions [#9515](python-pillow/Pillow#9515) \[[@radarhere](https://github.com/radarhere)] - Jeffrey A. Clark -> Jeffrey 'Alex' Clark [#9513](python-pillow/Pillow#9513) \[[@aclark4life](https://github.com/aclark4life)] - Add release notes for [#9394](python-pillow/Pillow#9394), [#9419](python-pillow/Pillow#9419) and [#9456](python-pillow/Pillow#9456) [#9467](python-pillow/Pillow#9467) \[[@radarhere](https://github.com/radarhere)] - Add Amiga Workbench .info loader to 3rd party plugins list [#9459](python-pillow/Pillow#9459) \[[@bitplane](https://github.com/bitplane)] - Merge PFM documentation into PPM [#9434](python-pillow/Pillow#9434) \[[@radarhere](https://github.com/radarhere)] - Update macOS tested Pillow versions [#9431](python-pillow/Pillow#9431) \[[@radarhere](https://github.com/radarhere)] - Fix CVE number [#9430](python-pillow/Pillow#9430) \[[@hugovk](https://github.com/hugovk)] #### Dependencies - Update xz to 5.8.3 [#9523](python-pillow/Pillow#9523) \[[@radarhere](https://github.com/radarhere)] - Update libjpeg-turbo to 3.1.4.1 [#9507](python-pillow/Pillow#9507) \[[@radarhere](https://github.com/radarhere)] - Update libpng to 1.6.56 [#9499](python-pillow/Pillow#9499) \[[@radarhere](https://github.com/radarhere)] - Update freetype to 2.14.3 [#9485](python-pillow/Pillow#9485) \[[@radarhere](https://github.com/radarhere)] - Updated libavif to 1.4.1 [#9479](python-pillow/Pillow#9479) \[[@radarhere](https://github.com/radarhere)] - Updated harfbuzz to 13.2.1 [#9461](python-pillow/Pillow#9461) \[[@radarhere](https://github.com/radarhere)] - Update Ghostscript to 10.7.0 [#9469](python-pillow/Pillow#9469) \[[@radarhere](https://github.com/radarhere)] - Update harfbuzz to 13.0.1 [#9453](python-pillow/Pillow#9453) \[[@radarhere](https://github.com/radarhere)] - Update libavif to 1.4.0 [#9460](python-pillow/Pillow#9460) \[[@radarhere](https://github.com/radarhere)] - Update freetype to 2.14.2 [#9449](python-pillow/Pillow#9449) \[[@radarhere](https://github.com/radarhere)] - Update actions/download-artifact action to v8 [#9451](python-pillow/Pillow#9451) \[@[renovate\[bot\]](https://github.com/apps/renovate)] - Updated libpng to 1.6.55 [#9425](python-pillow/Pillow#9425) \[[@radarhere](https://github.com/radarhere)] #### Testing - Cleanup .spider extension in the same test where it is added [#9517](python-pillow/Pillow#9517) \[[@radarhere](https://github.com/radarhere)] - Run tests in parallel via tox for 3.5x speedup [#9516](python-pillow/Pillow#9516) \[[@hugovk](https://github.com/hugovk)] - Enable colour in CI logs [#9486](python-pillow/Pillow#9486) \[[@hugovk](https://github.com/hugovk)] - Update Ghostscript to 10.7.0 [#9469](python-pillow/Pillow#9469) \[[@radarhere](https://github.com/radarhere)] - Simplify TGA test code [#9477](python-pillow/Pillow#9477) \[[@radarhere](https://github.com/radarhere)] - Update tests to check for ValueError when encoding an empty image [#9464](python-pillow/Pillow#9464) \[[@radarhere](https://github.com/radarhere)] - Upgrade CI from `macos-15-intel` to `macos-26-intel` [#9454](python-pillow/Pillow#9454) \[[@hugovk](https://github.com/hugovk)] - Add check-case-conflict hook [#9446](python-pillow/Pillow#9446) \[[@radarhere](https://github.com/radarhere)] - Specify platform when pulling docker image [#9440](python-pillow/Pillow#9440) \[[@radarhere](https://github.com/radarhere)] - GHA: Cache libavif and webp builds for Ubuntu [#9437](python-pillow/Pillow#9437) \[[@hugovk](https://github.com/hugovk)] - Update macOS tested Pillow versions [#9431](python-pillow/Pillow#9431) \[[@radarhere](https://github.com/radarhere)] #### Other changes - Check calloc return value [#9527](python-pillow/Pillow#9527) \[[@radarhere](https://github.com/radarhere)] - Check all allocs in the Arrow tree [#9488](python-pillow/Pillow#9488) \[[@wiredfool](https://github.com/wiredfool)] - Reject non-numeric elements inside list coords [#9526](python-pillow/Pillow#9526) \[[@hugovk](https://github.com/hugovk)] - Move variable declaration inside define [#9525](python-pillow/Pillow#9525) \[[@radarhere](https://github.com/radarhere)] - Resize tall images vertically first [#9524](python-pillow/Pillow#9524) \[[@radarhere](https://github.com/radarhere)] - Avoid overflow by not adding extents together [#9520](python-pillow/Pillow#9520) \[[@hugovk](https://github.com/hugovk)] - Use long for glyph position [#9518](python-pillow/Pillow#9518) \[[@hugovk](https://github.com/hugovk)] - Raise an error if the trailer chain loops back on itself [#9519](python-pillow/Pillow#9519) \[[@hugovk](https://github.com/hugovk)] - Only read as much data from gzip-decompressed data as necessary [#9521](python-pillow/Pillow#9521) \[[@hugovk](https://github.com/hugovk)] - Allow None extents in C setimage() [#9504](python-pillow/Pillow#9504) \[[@radarhere](https://github.com/radarhere)] - Use critical sections to protect FontObject [#9498](python-pillow/Pillow#9498) \[[@colesbury](https://github.com/colesbury)] - Add ImageText.Text.wrap() to wrap text [#9286](python-pillow/Pillow#9286) \[[@radarhere](https://github.com/radarhere)] - Always call StubHandler open() when opening StubImageFile [#9412](python-pillow/Pillow#9412) \[[@radarhere](https://github.com/radarhere)] - Improved BCn overflow check [#9043](python-pillow/Pillow#9043) \[[@radarhere](https://github.com/radarhere)] - Image will never be None [#9512](python-pillow/Pillow#9512) \[[@radarhere](https://github.com/radarhere)] - Raise EOFError when seeking too far in PSD [#9388](python-pillow/Pillow#9388) \[[@radarhere](https://github.com/radarhere)] - Raise error if ImageGrab subprocess gives non-zero returncode [#9321](python-pillow/Pillow#9321) \[[@radarhere](https://github.com/radarhere)] - Allow for different palette entry sizes when correcting BMP pixel data offset [#9472](python-pillow/Pillow#9472) \[[@radarhere](https://github.com/radarhere)] - Ignore unspecified extra samples for TIFF separate planar configuration [#9514](python-pillow/Pillow#9514) \[[@radarhere](https://github.com/radarhere)] - Add PERF to lint and fix findings [#9510](python-pillow/Pillow#9510) \[[@hugovk](https://github.com/hugovk)] - Switch iOS back to macos-15-intel [#9509](python-pillow/Pillow#9509) \[[@radarhere](https://github.com/radarhere)] - Catch struct.error [#9505](python-pillow/Pillow#9505) \[[@radarhere](https://github.com/radarhere)] - Check PyCapsule\_GetPointer and PyBytes\_FromStringAndSize return values [#9508](python-pillow/Pillow#9508) \[[@radarhere](https://github.com/radarhere)] - Fix missing null dereference checks [#9489](python-pillow/Pillow#9489) \[[@wiredfool](https://github.com/wiredfool)] - CI: Retry failed downloads [#9506](python-pillow/Pillow#9506) \[[@hugovk](https://github.com/hugovk)] - Use PyModule\_AddObjectRef [#9503](python-pillow/Pillow#9503) \[[@radarhere](https://github.com/radarhere)] - Release reference to encoder on error [#9500](python-pillow/Pillow#9500) \[[@radarhere](https://github.com/radarhere)] - Fixed AVIF and WEBP dealloc [#9501](python-pillow/Pillow#9501) \[[@radarhere](https://github.com/radarhere)] - Check PyType\_Ready return values [#9502](python-pillow/Pillow#9502) \[[@radarhere](https://github.com/radarhere)] - Check if PyObject\_CallMethod result is NULL [#9494](python-pillow/Pillow#9494) \[[@radarhere](https://github.com/radarhere)] - Do not use palette from grayscale or bilevel colorspace when reading JPEG2000 images [#9468](python-pillow/Pillow#9468) \[[@radarhere](https://github.com/radarhere)] - If TGA v2 extension area specifies no alpha, fill alpha channel [#9478](python-pillow/Pillow#9478) \[[@radarhere](https://github.com/radarhere)] - Set image pixels individually on 32-bit Windows [#9492](python-pillow/Pillow#9492) \[[@radarhere](https://github.com/radarhere)] - Add error messages before returning NULL when encoding [#9493](python-pillow/Pillow#9493) \[[@radarhere](https://github.com/radarhere)] - Fix `_getxy` refcount leaks [#9487](python-pillow/Pillow#9487) \[[@hugovk](https://github.com/hugovk)] - Fix invalid test font [#9483](python-pillow/Pillow#9483) \[[@radarhere](https://github.com/radarhere)] - Add Exif tag "FrameRate" [#9470](python-pillow/Pillow#9470) \[[@zhiyuanouyang](https://github.com/zhiyuanouyang)] - Support reading JPEG2000 images with CMYK palettes [#9456](python-pillow/Pillow#9456) \[[@radarhere](https://github.com/radarhere)] - Simplify `setimage()` by always passing extents [#9395](python-pillow/Pillow#9395) \[[@radarhere](https://github.com/radarhere)] - If bitmap buffer is empty, do not render anything [#8324](python-pillow/Pillow#8324) \[[@radarhere](https://github.com/radarhere)] - Change to ValueError when encoding an empty image [#9394](python-pillow/Pillow#9394) \[[@radarhere](https://github.com/radarhere)] - Add FontFile.to\_imagefont() [#9419](python-pillow/Pillow#9419) \[[@fjhenigman](https://github.com/fjhenigman)] - \[pre-commit.ci] pre-commit autoupdate [#9450](python-pillow/Pillow#9450) \[@[pre-commit-ci\[bot\]](https://github.com/apps/pre-commit-ci)] - Use walrus operator [#9448](python-pillow/Pillow#9448) \[[@radarhere](https://github.com/radarhere)] - Only close file handle in ImagePalette.save() if it was opened internally [#9444](python-pillow/Pillow#9444) \[[@bysiber](https://github.com/bysiber)] - Fix `self.decode` typo [#9445](python-pillow/Pillow#9445) \[[@bysiber](https://github.com/bysiber)] - Fix BMP RLE delta escape reading from wrong file position [#9443](python-pillow/Pillow#9443) \[[@bysiber](https://github.com/bysiber)] - Correct error check when encoding AVIF images [#9442](python-pillow/Pillow#9442) \[[@radarhere](https://github.com/radarhere)] - Fix unexpected error when saving zero dimension images [#9391](python-pillow/Pillow#9391) \[[@radarhere](https://github.com/radarhere)] - Use uppercase format ID for PALM [#9435](python-pillow/Pillow#9435) \[[@radarhere](https://github.com/radarhere)] </details> --- ### Configuration 📅 **Schedule**: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined). 🚦 **Automerge**: Disabled by config. Please merge this manually once you are satisfied. ♻ **Rebasing**: Whenever PR is behind base branch, or you tick the rebase/retry checkbox. 🔕 **Ignore**: Close this PR and you won't be reminded about this update again. --- - [ ] If you want to rebase/retry this PR, check this box --- This PR has been generated by [Renovate Bot](https://github.com/renovatebot/renovate).  Reviewed-on: https://git.tainton.uk/repos/webexmemebot/pulls/579 Reviewed-by: Luke Tainton <luke@tainton.uk> Co-authored-by: renovate[bot] <renovate-bot@git.tainton.uk> Co-committed-by: renovate[bot] <renovate-bot@git.tainton.uk>

radarhere added the GIF label Jan 12, 2026

radarhere mentioned this pull request Jan 12, 2026

Confusing errors when saving zero-dimension images instead of clear validation #9389

Closed

radarhere removed the GIF label Jan 12, 2026

radarhere changed the title ~~Fix unexpected error when saving zero dimension GIF~~ Fix unexpected error when saving zero dimension GIF and PCX Jan 12, 2026

radarhere force-pushed the gif_save branch 2 times, most recently from 876be85 to 4326110 Compare January 12, 2026 21:48

Fix unexpected error when saving image with zero dimension

bd16568

radarhere force-pushed the gif_save branch from 4326110 to bd16568 Compare January 13, 2026 05:14

radarhere changed the title ~~Fix unexpected error when saving zero dimension GIF and PCX~~ Fix unexpected error when saving zero dimension images Jan 13, 2026

hugovk merged commit a5c9eba into python-pillow:main Feb 16, 2026
56 checks passed

radarhere deleted the gif_save branch February 16, 2026 10:59

This was referenced Mar 8, 2026

Save all MODES as all SAVE formats #9447

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Update tests to check for ValueError when encoding an empty image #9464

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Fix unexpected error when saving zero dimension images#9391

Fix unexpected error when saving zero dimension images#9391
hugovk merged 1 commit intopython-pillow:mainfrom
radarhere:gif_save

radarhere commented Jan 12, 2026 •

edited by hugovk

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radarhere commented Jan 12, 2026 •

edited by hugovk

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