tentative fixes for issue #1440

Author: jswhit2

Changelog

@@ -1,3 +1,5 @@
+ version 1.7.4 (not yet released)
+ ================================
  version 1.7.3 (tag v1.7.3rel)
  =============================
  * Python 3.14 wheels (issue #1432)

include/netcdf-compat.h

@@ -60,7 +60,7 @@ static inline int nc_get_alignment(int* thresholdp, int* alignmentp) {
 #else
 #define HAS_NCRCSET 0
 static inline int nc_rc_set(const char* key, const char* value) { return NC_EINVAL; }
-static inline const char *nc_rc_get(const char* key) { return NC_EINVAL; }
+static inline const char *nc_rc_get(const char* key) { return NULL; }
 #endif
 
 #if NC_VERSION_GE(4, 4, 0)

src/netCDF4/_netCDF4.pyx

@@ -5525,7 +5525,11 @@ cannot be safely cast to variable data type""" % attname
                 # if data is a string or a bytes object, convert to a numpy string array
                 # whose length is equal to the rightmost dimension of the
                 # variable.
-                if type(data) in [str,bytes]: data = numpy.asarray(data,dtype='S'+repr(self.shape[-1]))
+                if type(data) in [str,bytes]:
+                    if encoding == 'ascii':
+                        data = numpy.asarray(data,dtype='S'+repr(self.shape[-1]))
+                    else:
+                        data = numpy.asarray(data,dtype='U'+repr(self.shape[-1]))
                 if data.dtype.kind in ['S','U'] and data.dtype.itemsize > 1:
                     # if data is a numpy string array, convert it to an array
                     # of characters with one more dimension.
@@ -6816,15 +6820,12 @@ returns a numpy string array with datatype `'UN'` (or `'SN'`) and shape
     dtype = b.dtype.kind
     if dtype not in ["S","U"]:
         raise ValueError("type must be string or unicode ('S' or 'U')")
-    if encoding in ['none','None','bytes']:
-        bs = b.tobytes()
-    else:
-        bs = b.tobytes().decode(encoding)
+    bs = b.tobytes()
     slen = int(b.shape[-1])
     if encoding in ['none','None','bytes']:
         a = numpy.array([bs[n1:n1+slen] for n1 in range(0,len(bs),slen)],'S'+repr(slen))
     else:
-        a = numpy.array([bs[n1:n1+slen] for n1 in range(0,len(bs),slen)],'U'+repr(slen))
+        a = numpy.array([bs[n1:n1+slen].decode(encoding) for n1 in range(0,len(bs),slen)],'U'+repr(slen))
     a.shape = b.shape[:-1]
     return a