From e9e42c9128936e06fa9f0c3e2e6378c42885072d Mon Sep 17 00:00:00 2001
From: David Manthey <david.manthey@kitware.com>
Date: Mon, 13 Dec 2021 09:08:43 -0500
Subject: [PATCH] Harden detecting file-not-found.

This handles some difference in the conda and pip installations of gdal.
---
 large_image/tilesource/__init__.py | 19 +++++++++++--------
 test/test_source_base.py           |  7 +++++++
 2 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/large_image/tilesource/__init__.py b/large_image/tilesource/__init__.py
index 6a3a43549..1f29a636d 100644
--- a/large_image/tilesource/__init__.py
+++ b/large_image/tilesource/__init__.py
@@ -31,14 +31,15 @@ def isGeospatial(path):
         ds = gdal.Open(path, gdalconst.GA_ReadOnly)
     except Exception:
         return False
-    if ds.GetGCPs() and ds.GetGCPProjection():
-        return True
-    if ds.GetProjection():
-        return True
-    if ds.GetGeoTransform(can_return_null=True):
-        return True
-    if ds.GetDriver().ShortName in {'NITF', 'netCDF'}:
-        return True
+    if ds:
+        if ds.GetGCPs() and ds.GetGCPProjection():
+            return True
+        if ds.GetProjection():
+            return True
+        if ds.GetGeoTransform(can_return_null=True):
+            return True
+        if ds.GetDriver().ShortName in {'NITF', 'netCDF'}:
+            return True
     return False
 
 
@@ -113,6 +114,8 @@ def getTileSourceFromDict(availableSources, pathOrUri, *args, **kwargs):
     sourceName = getSourceNameFromDict(availableSources, pathOrUri, *args, **kwargs)
     if sourceName:
         return availableSources[sourceName](pathOrUri, *args, **kwargs)
+    if not os.path.exists(pathOrUri) and '://' not in pathOrUri:
+        raise TileSourceFileNotFoundError(pathOrUri)
     raise TileSourceError('No available tilesource for %s' % pathOrUri)
 
 
diff --git a/test/test_source_base.py b/test/test_source_base.py
index d1693ccc0..81a0e88be 100644
--- a/test/test_source_base.py
+++ b/test/test_source_base.py
@@ -77,6 +77,13 @@ def testSourcesFileNotFound(source):
         large_image.tilesource.AvailableTileSources[source]('nosuchfile.ext')
 
 
+def testBaseFileNotFound():
+    with pytest.raises(large_image.exceptions.TileSourceFileNotFoundError):
+        large_image.open('nosuchfile')
+    with pytest.raises(large_image.exceptions.TileSourceFileNotFoundError):
+        large_image.open('nosuchfile.ext')
+
+
 @pytest.mark.parametrize('filename', registry)
 @pytest.mark.parametrize('source', SourceAndFiles)
 def testSourcesCanRead(source, filename):