Merge branch 'maint'

shapely/ctypes_declarations.py

@@ -14,7 +14,7 @@ class allocated_c_char_p(c_char_p):
     '''char pointer return type'''
     pass
 
-EXCEPTION_HANDLER_FUNCTYPE = CFUNCTYPE(None, c_char_p, c_char_p)
+EXCEPTION_HANDLER_FUNCTYPE = CFUNCTYPE(None, c_char_p, c_void_p)
 
 
 def prototype(lgeos, geos_version):

shapely/geos.py

@@ -2,11 +2,14 @@
 Proxies for libgeos, GEOS-specific exceptions, and utilities
 """
 
+import re
 import sys
 import atexit
 import logging
 import threading
-from ctypes import pointer, c_void_p, c_size_t, c_char_p, string_at
+from ctypes import CDLL, cdll, pointer, string_at, cast, POINTER
+from ctypes import c_void_p, c_size_t, c_char_p, c_int, c_float
+from ctypes.util import find_library
 
 from .ctypes_declarations import prototype, EXCEPTION_HANDLER_FUNCTYPE
 from .libgeos import lgeos as _lgeos, geos_version
@@ -80,19 +83,33 @@ class TopologicalError(Exception):
 class PredicateError(Exception):
     pass
 
-
-def error_handler(fmt, *args):
-    if sys.version_info[0] >= 3:
+# While this function can take any number of positional arguments when
+# called from Python and GEOS expects its error handler to accept any
+# number of arguments (like printf), I'm unable to get ctypes to make
+# a callback object from this function that will accept any number of
+# arguments.
+#
+# At the moment, functions in the GEOS C API only pass 0 or 1 arguments
+# to the error handler. We can deal with this, but when if that changes,
+# Shapely may break.
+
+def handler(level):
+    def callback(fmt, *args):
         fmt = fmt.decode('ascii')
-        args = [arg.decode('ascii') for arg in args]
-    LOG.error(fmt, *args)
-
-
-def notice_handler(fmt, args):
-    if sys.version_info[0] >= 3:
-        fmt = fmt.decode('ascii')
-        args = args.decode('ascii')
-    LOG.warning(fmt, args)
+        conversions = re.findall(r'%.', fmt)
+        log_vals = []
+        for spec, arg in zip(conversions, args):
+            if spec == '%s' and arg is not None:
+                log_vals.append(string_at(arg).decode('ascii'))
+            else:
+                LOG.error("An error occurred, but the format string "
+                          "'%s' could not be converted.", fmt)
+                return
+        getattr(LOG, level)(fmt, *log_vals)
+    return callback
+
+error_handler = handler('error')
+notice_handler = handler('warning')
 
 error_h = EXCEPTION_HANDLER_FUNCTYPE(error_handler)
 notice_h = EXCEPTION_HANDLER_FUNCTYPE(notice_handler)

tests/test_geos_err_handler.py

@@ -0,0 +1,33 @@
+import logging
+
+import pytest
+
+from shapely.geometry import LineString
+from shapely.geos import ReadingError
+from shapely.wkt import loads
+
+
+def test_error_handler(tmpdir):
+    logger = logging.getLogger('shapely.geos')
+    logger.setLevel(logging.DEBUG)
+
+    logfile = str(tmpdir.join('test_error.log'))
+    fh = logging.FileHandler(logfile)
+    logger.addHandler(fh)
+
+    # This operation calls error_handler with a format string that
+    # has *no* conversion specifiers.
+    LineString([(0, 0), (2, 2)]).project(LineString([(1, 1), (1.5, 1.5)]))
+
+    # This calls error_handler with a format string of "%s" and one
+    # value.
+    with pytest.raises(ReadingError):
+        loads('POINT (LOLWUT)')
+
+    g = loads('MULTIPOLYGON (((10 20, 10 120, 60 70, 30 70, 30 40, 60 40, 60 70, 90 20, 10 20)))')
+    assert g.is_valid == False
+
+    log = open(logfile).read()
+    assert "third argument of GEOSProject_r must be Point*" in log
+    assert "Expected number but encountered word: 'LOLWUT'" in log
+    assert "Ring Self-intersection at or near point 60 70" in log