* introduced MULLE_BUFFER_IS_SPRINTF_INFLEXIBLE for that sprintf use special case, to quiet a wrong assert

Author: mulle-nat

CMakeLists.txt

@@ -1,6 +1,6 @@
-cmake_minimum_required( VERSION 3.14)
+cmake_minimum_required( VERSION 3.13...99.99)
 
-project( mulle-buffer VERSION 5.0.0 LANGUAGES C)
+project( mulle-buffer VERSION 5.0.1 LANGUAGES C)
 
 
 ### mulle-sde environment

RELEASENOTES.md

@@ -1,3 +1,7 @@
+### 5.0.1
+
+* introduced `MULLE_BUFFER_IS_SPRINTF_INFLEXIBLE` for that sprintf use special case, to quiet a wrong assert
+
 # 5.0.0
 
 

src/mulle--buffer.c

@@ -59,7 +59,8 @@ void
    //
    // this is for mulle_sprintf, where we have API that gets storage, where
    // we don't know the size. We can't have buffer->_sentinel wrapping
-   // around though for our tests
+   // around though for our tests. Of course the crazy sentinel value,
+   // can't protect us from overwrites (but thats sprintf)
    //
    if( length == INT_MAX)
    {
@@ -68,9 +69,11 @@ void
          length >>= 1;
          buffer->_sentinel = &buffer->_storage[ length];
       }
+      buffer->_type = MULLE_BUFFER_IS_SPRINTF_INFLEXIBLE;
    }
-   buffer->_size             = length;
-   buffer->_type             = MULLE_BUFFER_IS_INFLEXIBLE;
+   else
+      buffer->_type = MULLE_BUFFER_IS_INFLEXIBLE;
+   buffer->_size = length;
 
    assert( buffer->_sentinel >= buffer->_storage);
 }

src/mulle--buffer.h

@@ -45,9 +45,10 @@ struct mulle_allocator;
 
 enum
 {
-  MULLE_BUFFER_IS_FLEXIBLE   = 0,
-  MULLE_BUFFER_IS_INFLEXIBLE = 1,
-  MULLE_BUFFER_IS_FLUSHABLE  = 2
+  MULLE_BUFFER_IS_FLEXIBLE           = 0,
+  MULLE_BUFFER_IS_INFLEXIBLE         = 1,
+  MULLE_BUFFER_IS_FLUSHABLE          = 2,
+  MULLE_BUFFER_IS_SPRINTF_INFLEXIBLE = 3  // sentinel is not trustworthy
 };
 
 
@@ -554,7 +555,11 @@ static inline int   _mulle__buffer_intersects_bytes( struct mulle__buffer *buffe
    unsigned char   *start;
    unsigned char   *end;
 
-   if( ! length)
+   // so if the buffer is MULLE_BUFFER_IS_SPRINTF_INFLEXIBLE (which it NEVER
+   // should be except when we are doing actually a sprintf implementation)
+   // the concept of intersection becomes meaningless, as the sentinel is
+   // way off
+   if( ! length || (buffer->_type & MULLE_BUFFER_IS_SPRINTF_INFLEXIBLE) == MULLE_BUFFER_IS_SPRINTF_INFLEXIBLE)
       return( 0);
 
    start = bytes;

src/mulle-buffer.h

@@ -39,7 +39,7 @@
 #ifndef mulle_buffer_h__
 #define mulle_buffer_h__
 
-#define MULLE__BUFFER_VERSION  ((5UL << 20) | (0 << 8) | 0)
+#define MULLE__BUFFER_VERSION  ((5UL << 20) | (0 << 8) | 1)
 
 #include "include.h"
 #include "mulle--buffer.h"