From ded2b9429c5399c9d6b3b5f125d36826211fde16 Mon Sep 17 00:00:00 2001
From: Ozan Tezcan <ozan.vx@gmail.com>
Date: Sun, 4 Apr 2021 12:58:07 +0300
Subject: [PATCH] sc_buf set_rpos and set_wpos checks. Don't compact on
 reserve. (#65)

* sc_buf set_rpos and set_wpos checks. Don't compact on reserve.
---
 buffer/buf_test.c |  9 +++++++++
 buffer/sc_buf.c   | 44 ++++++++++++++++++++++++--------------------
 2 files changed, 33 insertions(+), 20 deletions(-)

diff --git a/buffer/buf_test.c b/buffer/buf_test.c
index 0bc4c08..c9cb091 100644
--- a/buffer/buf_test.c
+++ b/buffer/buf_test.c
@@ -10,6 +10,15 @@ void test1()
     const char* xstr;
     struct sc_buf buf, buf2;
 
+    sc_buf_init(&buf, 100);
+    sc_buf_set_rpos(&buf, 1);
+    assert(sc_buf_valid(&buf) == false);
+    sc_buf_clear(&buf);
+    assert(sc_buf_valid(&buf) == true);
+    sc_buf_set_wpos(&buf, 101);
+    assert(sc_buf_valid(&buf) == false);
+    sc_buf_term(&buf);
+
     sc_buf_init(&buf, 100);
     sc_buf_init(&buf2, 100);
     sc_buf_put_str(&buf, "s");
diff --git a/buffer/sc_buf.c b/buffer/sc_buf.c
index 0c55933..4010b2f 100644
--- a/buffer/sc_buf.c
+++ b/buffer/sc_buf.c
@@ -93,30 +93,28 @@ bool sc_buf_reserve(struct sc_buf *buf, uint32_t len)
 
     if (buf->wpos + len > buf->cap) {
         if (buf->ref) {
-            return false;
+            goto error;
         }
 
-        sc_buf_compact(buf);
-
-        if (buf->wpos + len > buf->cap) {
-            size = ((buf->cap + len + 4095) / 4096) * 4096;
-            if (size > buf->limit || buf->cap >= SC_BUF_SIZE_MAX - 4096) {
-                buf->error |= SC_BUF_OOM;
-                return false;
-            }
-
-            tmp = sc_buf_realloc(buf->mem, size);
-            if (tmp == NULL) {
-                buf->error |= SC_BUF_OOM;
-                return false;
-            }
-
-            buf->cap = size;
-            buf->mem = tmp;
+        size = ((buf->cap + len + 4095) / 4096) * 4096;
+        if (size > buf->limit || buf->cap >= SC_BUF_SIZE_MAX - 4096) {
+            goto error;
         }
+
+        tmp = sc_buf_realloc(buf->mem, size);
+        if (tmp == NULL) {
+            goto error;
+        }
+
+        buf->cap = size;
+        buf->mem = tmp;
     }
 
     return true;
+
+error:
+    buf->error |= SC_BUF_OOM;
+    return false;
 }
 
 bool sc_buf_shrink(struct sc_buf *buf, uint32_t len)
@@ -182,13 +180,19 @@ uint32_t sc_buf_rpos(struct sc_buf *buf)
 
 void sc_buf_set_rpos(struct sc_buf *buf, uint32_t pos)
 {
-    assert(buf->wpos >= pos);
+    if (pos > buf->wpos) {
+        buf->error |= SC_BUF_CORRUPT;
+    }
+
     buf->rpos = pos;
 }
 
 void sc_buf_set_wpos(struct sc_buf *buf, uint32_t pos)
 {
-    assert(pos <= buf->cap);
+    if (pos > buf->cap) {
+        buf->error |= SC_BUF_CORRUPT;
+    }
+
     buf->wpos = pos;
 }