id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
37193	ogrinfo() does not validate num_features, so None and negative values give surprising results	Caleb Jeffery Teye		"django.contrib.gis.utils.ogrinfo(data_source, num_features=10) is documented (and named) as taking the number of features to display per layer. Internally, it passes the argument straight into a list slice:

# django/contrib/gis/utils/ogrinfo.py
for j, feature in enumerate(layer[:num_features]):
    ...

Because the value isn't validated, Python's slicing rules leak through and produce results that don't match what the parameter name implies:

>>> from django.contrib.gis.utils import ogrinfo
>>> ogrinfo(""cities.shp"", num_features=None)   # prints *every* feature, not none
>>> ogrinfo(""cities.shp"", num_features=-2)      # prints all features except the last two

A caller reasonably expecting num_features to mean ""how many features to show"" gets neither an error nor the requested count.

ogrinfo is exported in __all__, so this is public API. The fix should decide on the intended contract — most likely validating that num_features is a non-negative integer and raising TypeError/ValueError otherwise — and add tests. Any change in behaviour for None/negative input should be weighed for backwards compatibility (possibly a deprecation path).

Spotted while documenting ogrinfo() in #25927 — see the review discussion on [https://github.com/django/django/pull/21443 PR #21443]."	Cleanup/optimization	new	GIS	dev	Normal		ogrinfo		Unreviewed	0	0	0	0	0	0