test: Explicitly set encoding to utf8 when opening text files

These are text files but their encoding does not depend on the locale.
Not all of them require utf8 but it is better to fix it at something
to remove potential unpredictability.

This is necessary on FreeBSD where no locale is set by default,
and apparently Python defaults not only the terminal encoding to the locale
but that of every text file. So without LOCALE environment it defaults text
file encoding to ASCII. This causes problems with e.g. `bitcoin.conf`.

Luckily the locale doesn't affect the default encoding for str.encode() and
bytes.decode() on Python 3, so this is the only change necessary.

Github-Pull: #8840
Rebased-From: 30930e847e2483c7c8163cc581b392bc288250e9

3 files changed, 4 insertions, 4 deletions

diff --git a/qa/rpc-tests/test_framework/coverage.py b/qa/rpc-tests/test_framework/coverage.py
index 23fce61014..13b33869f5 100644
--- a/qa/rpc-tests/test_framework/coverage.py
+++ b/qa/rpc-tests/test_framework/coverage.py
@@ -50,7 +50,7 @@ class AuthServiceProxyWrapper(object):
         rpc_method = self.auth_service_proxy_instance._service_name
 
         if self.coverage_logfile:
-            with open(self.coverage_logfile, 'a+') as f:
+            with open(self.coverage_logfile, 'a+', encoding='utf8') as f:
                 f.write("%s\n" % rpc_method)
 
         return return_val
@@ -100,7 +100,7 @@ def write_all_rpc_commands(dirname, node):
         if line and not line.startswith('='):
             commands.add("%s\n" % line.split()[0])
 
-    with open(filename, 'w') as f:
+    with open(filename, 'w', encoding='utf8') as f:
         f.writelines(list(commands))
 
     return True
diff --git a/qa/rpc-tests/test_framework/netutil.py b/qa/rpc-tests/test_framework/netutil.py
index 573b06772d..b92a9f6e1c 100644
--- a/qa/rpc-tests/test_framework/netutil.py
+++ b/qa/rpc-tests/test_framework/netutil.py
@@ -58,7 +58,7 @@ def netstat(typ='tcp'):
     To get pid of all network process running on system, you must run this script
     as superuser
     '''
-    with open('/proc/net/'+typ,'r') as f:
+    with open('/proc/net/'+typ,'r',encoding='utf8') as f:
         content = f.readlines()
         content.pop(0)
     result = []
diff --git a/qa/rpc-tests/test_framework/util.py b/qa/rpc-tests/test_framework/util.py
index 53db1cc492..47cebf4f6e 100644
--- a/qa/rpc-tests/test_framework/util.py
+++ b/qa/rpc-tests/test_framework/util.py
@@ -157,7 +157,7 @@ def initialize_datadir(dirname, n):
     if not os.path.isdir(datadir):
         os.makedirs(datadir)
     rpc_u, rpc_p = rpc_auth_pair(n)
-    with open(os.path.join(datadir, "bitcoin.conf"), 'w') as f:
+    with open(os.path.join(datadir, "bitcoin.conf"), 'w', encoding='utf8') as f:
         f.write("regtest=1\n")
         f.write("rpcuser=" + rpc_u + "\n")
         f.write("rpcpassword=" + rpc_p + "\n")