genericvector: Fix and optimize function LoadDataFromFile

It's not necessary to initialize the vector with 0,
because the initial values are read from file.

Fix also an assertion when trying to read an empty file.

Signed-off-by: Stefan Weil <[email protected]>

ccutil/genericvector.h

@@ -366,14 +366,18 @@ typedef bool (*FileWriter)(const GenericVector<char>& data,
 // returning false on error.
 inline bool LoadDataFromFile(const STRING& filename,
                              GenericVector<char>* data) {
+  bool result = false;
   FILE* fp = fopen(filename.string(), "rb");
-  if (fp == NULL) return false;
-  fseek(fp, 0, SEEK_END);
-  size_t size = ftell(fp);
-  fseek(fp, 0, SEEK_SET);
-  data->init_to_size(static_cast<int>(size), 0);
-  bool result = fread(&(*data)[0], 1, size, fp) == size;
-  fclose(fp);
+  if (fp != NULL) {
+    fseek(fp, 0, SEEK_END);
+    size_t size = ftell(fp);
+    fseek(fp, 0, SEEK_SET);
+    if (size > 0) {
+      data->resize_no_init(size);
+      result = fread(&(*data)[0], 1, size, fp) == size;
+    }
+    fclose(fp);
+  }
   return result;
 }
 // The default FileWriter writes the vector of char to the filename file,