quiz: handle line continuation in data files correctly, switch to getline(3)

Specifically, the following quiz.db line

foo:\
bar

was parsed into "foo:bar\n", which made it impossible to answer correctly.

Bug reported and inital fix from Alex Karle, partially reworked by
yours truly, further input from millert@

diff --git a/games/quiz/quiz.c b/games/quiz/quiz.c
index 073c170..d4fd060 100644 (file)
--- a/games/quiz/quiz.c
+++ b/games/quiz/quiz.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: quiz.c,v 1.30 2018/08/24 11:14:49 mestre Exp $        */
+/*     $OpenBSD: quiz.c,v 1.31 2021/03/11 21:18:25 naddy Exp $ */
 /*     $NetBSD: quiz.c,v 1.9 1995/04/22 10:16:58 cgd Exp $     */
 
 /*-
@@ -48,7 +48,6 @@ static QE qlist;
 static int catone, cattwo, tflag;
 static u_int qsize;
 
-char   *appdstr(char *, const char *, size_t);
 void    downcase(char *);
 void    get_cats(char *, char *);
 void    get_file(const char *);
@@ -110,7 +109,8 @@ get_file(const char *file)
 {
        FILE *fp;
        QE *qp;
-       size_t len;
+       ssize_t len;
+       size_t qlen, size;
        char *lp;
 
        if ((fp = fopen(file, "r")) == NULL)
@@ -123,26 +123,36 @@ get_file(const char *file)
         */
        qp = &qlist;
        qsize = 0;
-       while ((lp = fgetln(fp, &len)) != NULL) {
+       qlen = 0;
+       lp = NULL;
+       size = 0;
+       while ((len = getline(&lp, &size, fp)) != -1) {
                if (lp[len - 1] == '\n')
-                       --len;
-               if (qp->q_text && qp->q_text[0] != '\0' &&
-                   qp->q_text[strlen(qp->q_text) - 1] == '\\')
-                       qp->q_text = appdstr(qp->q_text, lp, len);
-               else {
+                       lp[--len] = '\0';
+               if (qp->q_text)
+                       qlen = strlen(qp->q_text);
+               if (qlen > 0 && qp->q_text[qlen - 1] == '\\') {
+                       qp->q_text[--qlen] = '\0';
+                       qlen += len;
+                       qp->q_text = realloc(qp->q_text, qlen + 1);
+                       if (qp->q_text == NULL)
+                               errx(1, "realloc");
+                       strlcat(qp->q_text, lp, qlen + 1);
+               } else {
                        if ((qp->q_next = malloc(sizeof(QE))) == NULL)
                                errx(1, "malloc");
                        qp = qp->q_next;
-                       if ((qp->q_text = malloc(len + 1)) == NULL)
-                               errx(1, "malloc");
-                       /* lp may not be zero-terminated; cannot use strlcpy */
-                       strncpy(qp->q_text, lp, len);
-                       qp->q_text[len] = '\0';
+                       qp->q_text = strdup(lp);
+                       if (qp->q_text == NULL)
+                               errx(1, "strdup");
                        qp->q_asked = qp->q_answered = FALSE;
                        qp->q_next = NULL;
                        ++qsize;
                }
        }
+       free(lp);
+       if (ferror(fp))
+               err(1, "getline");
        (void)fclose(fp);
 }
 
@@ -318,32 +328,6 @@ next_cat(const char *s)
                }
 }
 
-char *
-appdstr(char *s, const char *tp, size_t len)
-{
-       char *mp;
-       const char *sp;
-       int ch;
-       char *m;
-
-       if ((m = malloc(strlen(s) + len + 1)) == NULL)
-               errx(1, "malloc");
-       for (mp = m, sp = s; (*mp++ = *sp++) != '\0'; )
-               ;
-       --mp;
-       if (*(mp - 1) == '\\')
-               --mp;
-
-       while ((ch = *mp++ = *tp++) && ch != '\n')
-               ;
-       if (*(mp - 2) == '\\')
-               mp--;
-       *mp = '\0';
-
-       free(s);
-       return (m);
-}
-
 void
 score(u_int r, u_int w, u_int g)
 {