assert: avoid, use DEBUGASSERT instead!

... as it does extra checks to actually work.

Reported-by: jonrumsey at github
Fixes #1504

lib/http2.c

@@ -784,7 +784,7 @@ static int on_begin_headers(nghttp2_session *session,
   /* This is trailer HEADERS started.  Allocate buffer for them. */
   DEBUGF(infof(data_s, "trailer field started\n"));
 
-  assert(stream->trailer_recvbuf == NULL);
+  DEBUGASSERT(stream->trailer_recvbuf == NULL);
 
   stream->trailer_recvbuf = Curl_add_buffer_init();
   if(!stream->trailer_recvbuf) {
@@ -1453,7 +1453,7 @@ static ssize_t http2_recv(struct connectdata *conn, int sockindex,
     infof(data, "%zu data bytes written\n", nread);
     if(stream->pauselen == 0) {
       DEBUGF(infof(data, "Unpaused by stream %u\n", stream->stream_id));
-      assert(httpc->pause_stream_id == stream->stream_id);
+      DEBUGASSERT(httpc->pause_stream_id == stream->stream_id);
       httpc->pause_stream_id = 0;
 
       stream->pausedata = NULL;

lib/memdebug.c

@@ -35,10 +35,6 @@
 #include "curl_memory.h"
 #include "memdebug.h"
 
-#ifndef HAVE_ASSERT_H
-#  define assert(x) Curl_nop_stmt
-#endif
-
 /*
  * Until 2011-08-17 libcurl's Memory Tracking feature also performed
  * automatic malloc and free filling operations using 0xA5 and 0x13
@@ -167,7 +163,7 @@ void *curl_domalloc(size_t wantedsize, int line, const char *source)
   struct memdebug *mem;
   size_t size;
 
-  assert(wantedsize != 0);
+  DEBUGASSERT(wantedsize != 0);
 
   if(countcheck("malloc", line, source))
     return NULL;
@@ -196,8 +192,8 @@ void *curl_docalloc(size_t wanted_elements, size_t wanted_size,
   struct memdebug *mem;
   size_t size, user_size;
 
-  assert(wanted_elements != 0);
-  assert(wanted_size != 0);
+  DEBUGASSERT(wanted_elements != 0);
+  DEBUGASSERT(wanted_size != 0);
 
   if(countcheck("calloc", line, source))
     return NULL;
@@ -223,7 +219,7 @@ char *curl_dostrdup(const char *str, int line, const char *source)
   char *mem;
   size_t len;
 
-  assert(str != NULL);
+  DEBUGASSERT(str != NULL);
 
   if(countcheck("strdup", line, source))
     return NULL;
@@ -247,7 +243,7 @@ wchar_t *curl_dowcsdup(const wchar_t *str, int line, const char *source)
   wchar_t *mem;
   size_t wsiz, bsiz;
 
-  assert(str != NULL);
+  DEBUGASSERT(str != NULL);
 
   if(countcheck("wcsdup", line, source))
     return NULL;
@@ -276,7 +272,7 @@ void *curl_dorealloc(void *ptr, size_t wantedsize,
 
   size_t size = sizeof(struct memdebug)+wantedsize;
 
-  assert(wantedsize != 0);
+  DEBUGASSERT(wantedsize != 0);
 
   if(countcheck("realloc", line, source))
     return NULL;
@@ -445,7 +441,7 @@ int curl_fclose(FILE *file, int line, const char *source)
 {
   int res;
 
-  assert(file != NULL);
+  DEBUGDEBUGASSERT(file != NULL);
 
   res=fclose(file);
 

lib/mprintf.c

@@ -5,7 +5,7 @@
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 1999 - 2016, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 1999 - 2017, Daniel Stenberg, <daniel@haxx.se>, et al.
  *
  * This software is licensed as described in the file COPYING, which
  * you should have received as part of this distribution. The terms
@@ -951,9 +951,7 @@ static int dprintf_formatf(
         /* NOTE NOTE NOTE!! Not all sprintf implementations return number of
            output characters */
         (sprintf)(work, formatbuf, p->data.dnum);
-#ifdef CURLDEBUG
-        assert(strlen(work) <= sizeof(work));
-#endif
+        DEBUGASSERT(strlen(work) <= sizeof(work));
         for(fptr=work; *fptr; fptr++)
           OUTCHAR(*fptr);
       }

lib/rand.c

@@ -121,7 +121,7 @@ CURLcode Curl_rand(struct Curl_easy *data, unsigned char *rnd, size_t num)
 {
   CURLcode result = CURLE_BAD_FUNCTION_ARGUMENT;
 
-  assert(num > 0);
+  DEBUGASSERT(num > 0);
 
   while(num) {
     unsigned int r;