Text color numbers change between 1.24.14 and 1.25.0

[stevesimmons]

Description of the bug

When upgrading PyMuPDF from 1.24.14 to 1.25.0, the reported text color codes have changed.

I tested this with this code:

import pymupdf
print(pymupdf.__version__)
flags = pymupdf.TEXT_PRESERVE_IMAGES | pymupdf.TEXT_PRESERVE_WHITESPACE | pymupdf.TEXT_CID_FOR_UNKNOWN_UNICODE
doc = pymupdf.open("0d4cb925de9d383e.pdf")
page = doc[0]
dicts = page.get_text('dict', flags=flags, sort=True)
seen = set()
for b_ctr, b in enumerate(dicts['blocks']):
     for l_ctr, l in enumerate(b.get('lines', [])):
        for s_ctr, s in enumerate(l['spans']):
            color = s.get('color')
            if color is not None and color  not in seen:
                seen.add(color)
                print(f"B{b_ctr}.L{l_ctr}.S{s_ctr}: {color:8}, hex {hex(color):6}")

With output for PyMuPDF version 1.24.14 having positive colours numbers:

1.24.14
B0.L0.S0:    44526, hex 0xadee
B2.L0.S0:        0, hex 0x0   
B6.L1.S0: 16777215, hex 0xffffff

and output for PyMuPDF version 1.25.0 having negative colour numbers:

1.25.0
B0.L0.S0: -16732433, hex -0xff5111
B2.L0.S0: -16777216, hex -0x1000000
B6.L0.S0:       -1, hex -0x1  

This will break any code using PyMuPDF to find text based on predetermined color codes!

As to what caused this, the MuPDF release notes (https://mupdf.com/releases/history) for 1.25.0 RC2 do say that color changed to rgba with the addition of alpha channel.... I can't find anything that seems related in the PyMuPDF github.

(Note also that grouping of text into blocks/lines/spans changed between 1.24.14 and 1.25.0.)

How to reproduce the bug

See description above.

PyMuPDF version

1.25.0

Operating system

Linux

Python version

3.11

[JorjMcKie]

Will be corrected in next version.