char read: add nullpad and variable test cases

Author: scivision

tests/test_string.py

@@ -15,4 +15,5 @@
 fn = Path(P.file).expanduser()
 
 with h5py.File(fn, "w") as f:
-    f["/str"] = "Hello World!"
+    f["/variable"] = "Hello World!"
+    f.create_dataset("/nullpad", dtype="S40", data="Hello World!")

tests/test_string_read.f90

@@ -4,7 +4,7 @@ program main
 
 implicit none (type, external)
 
-character(1000) :: pyp, str
+character(1000) :: pyp, vstr, fstr
 integer :: i
 
 type(hdf5_file) :: h
@@ -14,12 +14,14 @@ program main
 
 call h%open(pyp, "r")
 
-call h%read("/str", str)
+call h%read("/variable", vstr)
+if(vstr /= "Hello World!") error stop "h5py read variable length failed: " // trim(vstr)
 
-call h%close()
+call h%read("/nullpad", fstr)
+if(fstr /= "Hello World!") error stop "h5py read null pad failed: " // trim(fstr)
 
-if(str /= "Hello World!") error stop "h5py read failed: " // trim(str)
+call h%close()
 
-print *, "OK: variable length string read"
+print *, "OK: variable/nullpad length string read"
 
 end program