Change how empty `Text` parameters are treated

Before even no input would be interpreted as an empty `Text` parameter,
but now one has to explicitly as "", '' or ``.

sources/Commands/CommandParser.uc

@@ -523,9 +523,25 @@ private final function bool ParseTextValue(
     AssociativeArray    parsedParameters,
     Command.Parameter   expectedParameter)
 {
+    local bool                  failedParsing;
     local string                textValue;
-    commandParser.Skip().MStringS(textValue);
-    if (!commandParser.Ok()) {
+    local parser.ParserState    initialState;
+    //  TODO: use parsing methods into `Text`
+    //  (needs some work for reading formatting `string`s from `Text` objects)
+    initialState = commandParser.Skip().GetCurrentState();
+    //  Try manually parsing as a string literal first, since then we will
+    //  allow empty `textValue` as a result
+    commandParser.MStringLiteralS(textValue);
+    failedParsing = !commandParser.Ok();
+    //  Otherwise - empty values are not allowed
+    if (failedParsing)
+    {
+        commandParser.RestoreState(initialState).MStringS(textValue);
+        failedParsing = (!commandParser.Ok() || textValue == "");
+    }
+    if (failedParsing)
+    {
+        commandParser.Fail();
         return false;
     }
     RecordParameter(parsedParameters, expectedParameter,

sources/Commands/Tests/TEST_Command.uc

@@ -394,7 +394,7 @@ defaultproperties
     queryAFailure2 = "simple fal"
 
     queryBSuccess1 = "[7, null] --values 1 3 5 2 4 text"
-    queryBSuccess2 = "do --type \"value\" -va 8 -sV --forced -T"
+    queryBSuccess2 = "do --type \"value\" -va 8 -sV --forced -T  \"\" "
     //  long then same as short
     queryBFailure1 = "[] 8 -tv 13"
     queryBFailure2 = "do 7 5 -sfV --forced yes"