Basic multiline buffer concept

src/pdf_browser/basic.h

@@ -87,6 +87,7 @@ T ClampBottom(T bottom, T b) {
 
 template <class T>
 T Clamp(T value, T min, T max) {
+    Assert(max >= min);
     if (value > max) return max;
     if (value < min) return min;
     return value;
@@ -151,6 +152,7 @@ inline void *AllocSize(Allocator alo, size_t size) {
 
 template <class T>
 void Dealloc(Allocator alo, T **p) {
+    if (*p == NULL) return;
     alo.proc(alo.object, AllocatorKind_Deallocate, *p, 0);
     *p = NULL;
 }