Revert "move extend out of users_file.c to sbuff.c"

This reverts commit 02ec7cd.

it turns out extending things in the sbuff code causes other
problems.  So we leave some hacks in the users_file parser.

src/lib/server/users_file.c

@@ -303,6 +303,8 @@ int pairlist_read(TALLOC_CTX *ctx, fr_dict_t const *dict, char const *file, PAIR
 		bool		leading_spaces;
 		PAIR_LIST	*t;
 
+		fr_sbuff_extend_lowat(NULL, &sbuff, 1024);
+
 		/*
 		 *	If the line is empty or has only comments,
 		 *	then we don't care about leading spaces.
@@ -391,6 +393,8 @@ int pairlist_read(TALLOC_CTX *ctx, fr_dict_t const *dict, char const *file, PAIR
 		comma = false;
 
 check_item:
+		fr_sbuff_extend_lowat(NULL, &sbuff, 1024);
+
 		/*
 		 *	Skip spaces before the item, and allow the
 		 *	check list to end on comment or LF.
@@ -523,6 +527,8 @@ int pairlist_read(TALLOC_CTX *ctx, fr_dict_t const *dict, char const *file, PAIR
 		comma = false;
 
 reply_item:
+		fr_sbuff_extend_lowat(NULL, &sbuff, 1024);
+
 		/*
 		 *	Reply items start with spaces.  If there's no
 		 *	spaces, then the current entry is done.  Add

src/lib/util/sbuff.c

@@ -700,7 +700,7 @@ size_t fr_sbuff_out_bstrncpy(fr_sbuff_t *out, fr_sbuff_t *in, size_t len)
 
 		remaining = (len - fr_sbuff_used_total(&our_in));
 
-		if (!fr_sbuff_extend_lowat(NULL, &our_in, 32)) break;
+		if (!fr_sbuff_extend(&our_in)) break;
 
 		chunk_len = fr_sbuff_remaining(&our_in);
 		if (chunk_len > remaining) chunk_len = remaining;
@@ -741,7 +741,7 @@ ssize_t fr_sbuff_out_bstrncpy_exact(fr_sbuff_t *out, fr_sbuff_t *in, size_t len)
 		ssize_t copied;
 
 		remaining = (len - fr_sbuff_used_total(&our_in));
-		if (remaining && !fr_sbuff_extend_lowat(NULL, &our_in, 32)) return 0;
+		if (remaining && !fr_sbuff_extend(&our_in)) return 0;
 
 		chunk_len = fr_sbuff_remaining(&our_in);
 		if (chunk_len > remaining) chunk_len = remaining;
@@ -788,7 +788,7 @@ size_t fr_sbuff_out_bstrncpy_allowed(fr_sbuff_t *out, fr_sbuff_t *in, size_t len
 		char	*p;
 		char	*end;
 
-		if (!fr_sbuff_extend_lowat(NULL, &our_in, 32)) break;
+		if (!fr_sbuff_extend(&our_in)) break;
 
 		p = fr_sbuff_current(&our_in);
 		end = CONSTRAINED_END(&our_in, len, fr_sbuff_used_total(&our_in));
@@ -1748,7 +1748,7 @@ size_t fr_sbuff_adv_past_allowed(fr_sbuff_t *sbuff, size_t len, bool
 	while (total < len) {
 		char *end;
 
-		if (!fr_sbuff_extend_lowat(NULL, sbuff, 32)) break;
+		if (!fr_sbuff_extend(sbuff)) break;
 
 		end = CONSTRAINED_END(sbuff, len, total);
 		p = sbuff->p;
@@ -1923,7 +1923,7 @@ char *fr_sbuff_adv_to_chr(fr_sbuff_t *sbuff, size_t len, char c)
 		char const	*found;
 		char		*end;
 
-		if (!fr_sbuff_extend_lowat(NULL, &our_sbuff, 32)) break;
+		if (!fr_sbuff_extend(&our_sbuff)) break;
 
 		end = CONSTRAINED_END(sbuff, len, total);
 		found = memchr(our_sbuff.p, c, end - our_sbuff.p);