Return -1 instead of 0 upon reaching EOF. This is somewhat ill-advised

because it means getdelim() returns -1 for both error and EOF, and
never returns 0. However, this is what the original GNU	implementation
does, and POSIX inherited the bug.

Reported by:	marcus@

lib/libc/stdio/getdelim.c

@@ -120,7 +120,6 @@ getdelim(char ** __restrict linep, size_t * __restrict linecapp, int delim,
 		goto error;
 	}
 
-	linelen = 0;
 	if (*linecapp == 0)
 		*linep = NULL;
 
@@ -128,9 +127,12 @@ getdelim(char ** __restrict linep, size_t * __restrict linecapp, int delim,
 		/* If fp is at EOF already, we just need space for the NUL. */
 		if (__sferror(fp) || expandtofit(linep, 1, linecapp))
 			goto error;
-		goto done;
+		FUNLOCKFILE(fp);
+		(*linep)[0] = '\0';
+		return (-1);
 	}
 
+	linelen = 0;
 	while ((endp = memchr(fp->_p, delim, fp->_r)) == NULL) {
 		if (sappend(linep, &linelen, linecapp, fp->_p, fp->_r))
 			goto error;

lib/libc/stdio/getline.3

@@ -24,7 +24,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd February 28, 2009
+.Dd March 29, 2009
 .Dt GETLINE 3
 .Os
 .Sh NAME
@@ -79,7 +79,7 @@ and
 functions return the number of characters written, excluding the
 terminating
 .Dv NUL .
-The value \-1 is returned if an error occurs.
+The value \-1 is returned if an error occurs, or if end-of-file is reached.
 .Sh EXAMPLES
 The following code fragment reads lines from a file and
 writes them to standard output.

tools/regression/lib/libc/stdio/test-getdelim.c

@@ -100,7 +100,7 @@ main(int argc, char *argv[])
 		assert(line[0] == '\0' && line[1] == '\0');
 		/* Third line: EOF */
 		line[0] = 'X';
-		assert(getline(&line, &linecap, fp) == 0);
+		assert(getline(&line, &linecap, fp) == -1);
 		assert(line[0] == '\0');
 		free(line);
 		assert(feof(fp));
@@ -139,7 +139,7 @@ main(int argc, char *argv[])
 	free(line);
 	line = NULL;
 	linecap = 0;
-	assert(getline(&line, &linecap, fp) == 0);
+	assert(getline(&line, &linecap, fp) == -1);
 	assert(line[0] == '\0');
 	assert(linecap > 0);
 	assert(errno == 0);