From 01c2d20dfde866d4bbed9a416cfbed8485156dd1 Mon Sep 17 00:00:00 2001
From: Vincent Gao <gaobing1230@gmail.com>
Date: Wed, 29 Jul 2026 04:29:00 +0200
Subject: [PATCH] Accept upper-case base32 in the pure-Python decoder

The _geohash extension's build_base32_decode_map accepts upper-case
base32 letters, but the pure-Python fallback's _base32_map is
lower-case only, so decode/decode_exactly/bbox/neighbors/expand raise a
bare KeyError on an upper-case geohash whenever the extension is not
built. Populate _base32_map with the upper-case keys as well, and raise
ValueError with the same message the extension reports for a character
outside the alphabet instead of leaking KeyError.
---
 geohash.py            | 12 +++++++++-
 tests/test_geohash.py | 52 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 63 insertions(+), 1 deletion(-)

diff --git a/geohash.py b/geohash.py
index 89a19c8..89e7f20 100644
--- a/geohash.py
+++ b/geohash.py
@@ -14,6 +14,11 @@
 _base32_map = {}
 for i in range(len(_base32)):
 	_base32_map[_base32[i]] = i
+	# The _geohash extension accepts upper-case base32 letters (see
+	# build_base32_decode_map in src/geohash_core.rs); mirror that here so the
+	# pure-Python fallback decodes the same codes the extension does.
+	if _base32[i].isalpha():
+		_base32_map[_base32[i].upper()] = i
 del i
 
 LONG_ZERO = 0
@@ -146,7 +151,12 @@ def _decode_c2i(hashcode):
 	lat_length = 0
 	lon_length = 0
 	for i in hashcode:
-		t = _base32_map[i]
+		try:
+			t = _base32_map[i]
+		except KeyError:
+			# Match the extension's error (map_error in src/lib.rs) instead of
+			# leaking a bare KeyError for an out-of-alphabet character.
+			raise ValueError("geohash code is [0123456789bcdefghjkmnpqrstuvwxyz]+") from None
 		if bit_length%2==0:
 			lon = lon<<3
 			lat = lat<<2
diff --git a/tests/test_geohash.py b/tests/test_geohash.py
index 6cf3c6e..07a3db6 100644
--- a/tests/test_geohash.py
+++ b/tests/test_geohash.py
@@ -92,5 +92,57 @@ def test_one(self):
 		self.assertEqual(set(['w', 'x', 'y', '8', 'b']), set(geohash.neighbors("z")))
 		self.assertEqual(set(['2', '6', '1', '0', '4', '9', '8', 'd']), set(geohash.neighbors("3")))
 
+class TestUpperCase(unittest.TestCase):
+	# The _geohash extension accepts upper-case base32 letters, so the
+	# pure-Python fallback (used whenever the extension is not built, e.g. the
+	# README's "copy geohash.py" path and every non-x86_64-Linux install) must
+	# decode the same codes to the same result.
+	codes = ['ezs42', 'u4pruydqqvj', 'dr5regw3pg', 'sunny', 'bgr96qxvpd46']
+
+	def test_decode_upper_equals_lower(self):
+		for code in self.codes:
+			self.assertEqual(geohash.decode(code.upper()), geohash.decode(code))
+
+	def test_decode_exactly_upper_equals_lower(self):
+		for code in self.codes:
+			self.assertEqual(geohash.decode_exactly(code.upper()), geohash.decode_exactly(code))
+
+	def test_bbox_upper_equals_lower(self):
+		for code in self.codes:
+			self.assertEqual(geohash.bbox(code.upper()), geohash.bbox(code))
+
+	def test_neighbors_upper_equals_lower(self):
+		for code in self.codes:
+			self.assertEqual(set(geohash.neighbors(code.upper())), set(geohash.neighbors(code)))
+
+	def test_expand_upper_equals_lower(self):
+		for code in self.codes:
+			expanded = geohash.expand(code.upper())
+			self.assertIn(code.upper(), expanded)
+			self.assertEqual(set(expanded) - {code.upper()}, set(geohash.neighbors(code)))
+
+	def test_mixed_case(self):
+		self.assertEqual(geohash.decode('Ezs42'), geohash.decode('ezs42'))
+		self.assertEqual(geohash.decode('eZS42'), geohash.decode('ezs42'))
+
+	def test_every_base32_letter_uppercases(self):
+		for c in '0123456789bcdefghjkmnpqrstuvwxyz':
+			code = 'e' + c + 's'
+			self.assertEqual(geohash.decode(code.upper()), geohash.decode(code))
+
+class TestInvalidCode(unittest.TestCase):
+	# Letters a, i, l, o (and their upper-case forms) are not in the geohash
+	# base32 alphabet; the extension raises ValueError for them, so the
+	# fallback must too rather than leaking a bare KeyError.
+	invalid = ['abc', 'io', 'ezs42a', 'ezs42L', 'EZS42O', 'ezs 42', 'ezs42!', 'A', 'I', 'l', 'o']
+
+	def test_invalid_char_raises_value_error(self):
+		for code in self.invalid:
+			for fn in (geohash.decode, geohash.decode_exactly, geohash.bbox,
+			           geohash.neighbors, geohash.expand):
+				with self.assertRaises(ValueError):
+					fn(code)
+
+
 if __name__=='__main__':
 	unittest.main()