Fixed a bug whereby Guild would always return a success

Also handled error checking on NotFound so that the propper handling can be done.

redbot/cogs/mod/mutes.py

@@ -22,7 +22,8 @@ mute_unmute_issues = {
         "permission and the user I'm muting must be "
         "lower than myself in the role hierarchy."
     ),
-    "left_guild": _("The user has left the server while we're applying an overwrite."),
+    "left_guild": _("The user has left the server while were applying an overwrite."),
+    "unknown_channel": _("The channel I tried to mute the user in isn't found."),
 }
 _ = T_
 
@@ -252,12 +253,19 @@ class MuteMixin(MixinMeta):
         author = ctx.message.author
         guild = ctx.guild
         audit_reason = get_audit_reason(author, reason)
+        guild_success = True
 
         mute_success = []
         for channel in guild.channels:
             success, issue = await self.mute_user(guild, channel, author, user, audit_reason)
             mute_success.append((success, issue))
             await asyncio.sleep(0.1)
+
+            if success is False:  # Check the latest entry
+                guild_success = False
+                break
+
+        if guild_success:
             try:
                 await modlog.create_case(
                     self.bot,
@@ -273,6 +281,8 @@ class MuteMixin(MixinMeta):
             except RuntimeError as e:
                 await ctx.send(e)
             await ctx.send(_("User has been muted in this server."))
+        else:
+            await ctx.channel.send(issue)
 
     @commands.group()
     @commands.guild_only()
@@ -369,12 +379,19 @@ class MuteMixin(MixinMeta):
         guild = ctx.guild
         author = ctx.author
         audit_reason = get_audit_reason(author, reason)
+        guild_success = True
 
         unmute_success = []
         for channel in guild.channels:
             success, message = await self.unmute_user(guild, channel, author, user, audit_reason)
             unmute_success.append((success, message))
             await asyncio.sleep(0.1)
+
+            if success is False:  # Check the latest entry
+                guild_success = False
+                break
+
+        if guild_success:
             try:
                 await modlog.create_case(
                     self.bot,
@@ -389,6 +406,23 @@ class MuteMixin(MixinMeta):
             except RuntimeError as e:
                 await ctx.send(e)
             await ctx.send(_("User has been unmuted in this server."))
+        else:
+            await ctx.channel.send(issue)
+
+    # Reference to L#13 for errors
+    # Kill muting on the following errors:
+    # Kill the mutes with returning False
+    # is_admin
+    # hierarchy_problem
+    # left_guild
+    # permissions_issue
+    #
+    # Keep alive on the following errors:
+    # Keep the muting going with None
+    # unknown_channel
+    # already_muted
+    #
+    # Else return True
 
     async def mute_user(
         self,
@@ -412,7 +446,7 @@ class MuteMixin(MixinMeta):
             new_overs.update(send_messages=False, add_reactions=False)
 
         if all(getattr(permissions, p) is False for p in new_overs.keys()):
-            return False, _(mute_unmute_issues["already_muted"])
+            return None, _(mute_unmute_issues["already_muted"])
 
         elif not await is_allowed_by_hierarchy(self.bot, self.settings, guild, author, user):
             return False, _(mute_unmute_issues["hierarchy_problem"])
@@ -423,7 +457,10 @@ class MuteMixin(MixinMeta):
             await channel.set_permissions(user, overwrite=overwrites, reason=reason)
         except discord.Forbidden:
             return False, _(mute_unmute_issues["permissions_issue"])
-        except discord.NotFound:
+        except discord.NotFound as e:
+            if e.code == 10003:
+                return None, _(mute_unmute_issues["unknown_channel"])
+            elif e.code == 10009:
                 return False, _(mute_unmute_issues["left_guild"])
         else:
             await self.settings.member(user).set_raw(
@@ -463,7 +500,10 @@ class MuteMixin(MixinMeta):
                 await channel.set_permissions(user, overwrite=overwrites, reason=reason)
         except discord.Forbidden:
             return False, _(mute_unmute_issues["permissions_issue"])
-        except discord.NotFound:
+        except discord.NotFound as e:
+            if e.code == 10003:
+                return None, _(mute_unmute_issues["unknown_channel"])
+            elif e.code == 10009:
                 return False, _(mute_unmute_issues["left_guild"])
         else:
             await self.settings.member(user).clear_raw("perms_cache", str(channel.id))