Breaking changes and versioning

[thesoulless]

I'm a bit confused how libvips versioning works.

Add "keep" flag to savers was merged and released in v8.15, which adds a great unified flag to all the savers. But if I'm not mistaken strip was never marked as deprecated, and so removing it seems like a breaking change.

Or maybe the savers stability is not considered in the versioning?

[jcupitt]

Hello @thesoulless,

I think strip has been tagged as deprecated, hasn't it? If I run:

$ vips jpegsave
save image to jpeg file
usage:
   jpegsave in filename [--option-name option-value ...]
where:
   in           - Image to save, input VipsImage
   filename     - Filename to save to, input gchararray
optional arguments:
   Q            - Q factor, input gint
			default: 75
			min: 1, max: 100
   optimize-coding - Compute optimal Huffman coding tables, input gboolean
			default: false
   interlace    - Generate an interlaced (progressive) jpeg, input gboolean
			default: false
   trellis-quant - Apply trellis quantisation to each 8x8 block, input gboolean
			default: false
   overshoot-deringing - Apply overshooting to samples with extreme values, input gboolean
			default: false
   optimize-scans - Split spectrum of DCT coefficients into separate scans, input gboolean
			default: false
   quant-table  - Use predefined quantization table with given index, input gint
			default: 0
			min: 0, max: 8
   subsample-mode - Select chroma subsample operation mode, input VipsForeignSubsample
			default enum: auto
			allowed enums: auto, on, off
   restart-interval - Add restart markers every specified number of mcu, input gint
			default: 0
			min: 0, max: 2147483647
   keep         - Which metadata to retain, input VipsForeignKeep
			default flags: exif:xmp:iptc:icc:other:all
			allowed flags: none, exif, xmp, iptc, icc, other, all
   background   - Background value, input VipsArrayDouble
   page-height  - Set page height for multipage save, input gint
			default: 0
			min: 0, max: 10000000
   profile      - Filename of ICC profile to embed, input gchararray
operation flags: sequential nocache 

The new keep options is there, but strip has vanished. You can still use it (for compatibility), but it's no longer documented.

$ vips copy k2.jpg x.jpg[strip]
$

[thesoulless]

So it was marked as deprecated in the same release, and kept around for compatibility, I see.

My script was checking the vips jpegsave output and throw a waning since it couldn't find the strip flag anymore, but that's not how you mark a flag as deprecated in libvips.

Thanks for your time @jcupitt

[jcupitt]

That's right, it's the same in all the language bindings too -- the DEPRECATED flag on the argument means that it has vanished from all the pyvips docs and IDE completions, for example, but you can still use it.