LINE INPUT control code fix #1

In all the dialects I've worked with I've never seen LINE INPUT alter
anything but EOL characters on input. The only thing it did with EOL
was stop and leave them out of the resulting string.

This is fixes that issue but it needs further scrutiny to see if it
breaks anything else and / or if a similar patch is needed somewhere
else.

I can now count the number of times a line is started with a tab!! 8-)

bwb_inp.c

@@ -2776,7 +2776,25 @@ bwb_LINE_INPUT (LineType * Line)
     if (fgets (tbuf, tlen, My->CurrentFile->cfp))        /* bwb_LINE_INPUT */
     {
       tbuf[tlen] = NulChar;
-      CleanTextInput (tbuf);
+      /* jaf-20211006 CleanTextInput() converts all <' ' chars to ' '. None of
+         the dialects I've used did this with `LINE INPUT ...` You could read a
+         whole file, verbatim, control codes and all (other than EOL), assuming
+         it had line breaks frequently enough. I was just going to patch
+         CleanTextInput, but it appears it may have valid uses in other
+         contexts. So lets replace the call to it with a simple EOL filter.
+         Depending on OS and compiler and since we're not opening files in
+         "text" mode we'll strip off up to two CRs or LFs. This means that CRLF
+         endings will be handled the same as LF, even on UNIX. I don't think
+         this will cause problems... I think its an advantage.
+      //CleanTextInput (tbuf); */
+      tlen=strlen(tbuf);
+      if(tlen--) {
+        if(tbuf[tlen]=='\r' || tbuf[tlen]=='\n') {
+          tlen--;
+          if(tlen>=0 && (tbuf[tlen]=='\r' || tbuf[tlen]=='\n')) tlen--;
+          tbuf[tlen+1] = NulChar;
+        }
+      }
     }
     else
     {