Replaced "fgets" with a "get_token" function in demo/mtest_opponent.c

[czurnieden]

We shouldn't leave the clean-up of the mtest-tokens to mp_read_radix. This PR would also allow to get rid of the abominable input-sanitizing in #499

[sjaeckel]

Tests broken, something like the following "solves the problem"^TM (not sure what other problems it introduces ;) )

diff --git a/demo/mtest_opponent.c b/demo/mtest_opponent.c
index 9f80e65..dbf8745 100644
--- a/demo/mtest_opponent.c
+++ b/demo/mtest_opponent.c
@@ -21,3 +21,3 @@ static char *s_mp_get_token(char *s, int size, FILE *stream)
    char *s_bar = s;
-   int c;
+   int c, eol_hit = 0;
 
@@ -35,4 +35,9 @@ static char *s_mp_get_token(char *s, int size, FILE *stream)
       if ((c == '\n')  || (c == '\r')) {
+         eol_hit = 1;
          continue;
       }
+      if (eol_hit) {
+         ungetc(c, stream);
+         break;
+      }
       *s_bar++ = c;
@@ -110,3 +115,2 @@ static int mtest_opponent(void)
       GET_TOKEN(cmd, 4095, stdin);
-      cmd[strlen(cmd) - 1u] = '\0';
       printf("%-6s ]\r", cmd);

[czurnieden]

Tests broken

I always try not to leave my PRs broken but Travis took way too long to start that day^Wnight so I went to bed. Sorry!
(Why didn't it come up when I run --test-vs-mtest locally? That's annoying!)

not sure what other problems it introduces

Good question. I'll take a deeper look this time.

Thanks!

[czurnieden]

Does seem to work, now that s_mp_get_token stops at the right time.
Spot-checked input/output (If the names gets over correctly and the numbers for sub_d).

Why the local tests did fail before PR is still a mystery to me, because now they do. But I also forgot to remove cmd[strlen(cmd) - 1u] = '\0';, so it was most likely me to blame here.

There is still a non-technical problem left: because of the age of this part (read_radix) of LTM there might be many uses of the undocumented feature of read_radix to accept linebreaks at the end of the input string. This PR won't break them but if this PR gets included I can and will remove the input cleaning in #499 which will break those builds.
I admit I'm a bit torn here.