Increase limit and add assertions for deserialization of large arrays

One of the checks was too restrictive, as lstmeval deserializes
char arrays with 14000000 elements, so raise the limit to 30000000.
That check was added in commit 992031e.

Add also assertions which help finding such problems in debug mode.

Signed-off-by: Stefan Weil <stweil@ub-backup.bib.uni-mannheim.de>

Author: Stefan Weil

src/ccutil/genericvector.h

@@ -568,7 +568,10 @@ class PointerVector : public GenericVector<T*> {
     if (fread(&reserved, sizeof(reserved), 1, fp) != 1) return false;
     if (swap) Reverse32(&reserved);
     // Arbitrarily limit the number of elements to protect against bad data.
-    if (reserved > UINT16_MAX) return false;
+    assert(reserved <= UINT16_MAX);
+    if (reserved > UINT16_MAX) {
+      return false;
+    }
     GenericVector<T*>::reserve(reserved);
     truncate(0);
     for (uint32_t i = 0; i < reserved; ++i) {
@@ -949,6 +952,7 @@ bool GenericVector<T>::DeSerialize(bool swap, FILE* fp) {
   if (fread(&reserved, sizeof(reserved), 1, fp) != 1) return false;
   if (swap) Reverse32(&reserved);
   // Arbitrarily limit the number of elements to protect against bad data.
+  assert(reserved <= UINT16_MAX);
   if (reserved > UINT16_MAX) return false;
   reserve(reserved);
   size_used_ = reserved;
@@ -964,7 +968,8 @@ bool GenericVector<T>::DeSerialize(tesseract::TFile* fp) {
   uint32_t reserved;
   if (fp->FReadEndian(&reserved, sizeof(reserved), 1) != 1) return false;
   // Arbitrarily limit the number of elements to protect against bad data.
-  if (reserved > UINT16_MAX) return false;
+  assert(reserved <= 30000000);
+  if (reserved > 30000000) return false;
   reserve(reserved);
   size_used_ = reserved;
   return fp->FReadEndian(data_, sizeof(T), size_used_) == size_used_;