1 files changed, 4 insertions, 3 deletions
diff --git a/src/util/readwritefile.cpp b/src/util/readwritefile.cpp
index a45c41d367..3ec08119e7 100644
--- a/src/util/readwritefile.cpp
+++ b/src/util/readwritefile.cpp
@@ -5,8 +5,9 @@
 
 #include <fs.h>
 
+#include <algorithm>
+#include <cstdio>
 #include <limits>
-#include <stdio.h>
 #include <string>
 #include <utility>
 
@@ -18,7 +19,7 @@ std::pair<bool,std::string> ReadBinaryFile(const fs::path &filename, size_t maxs
     std::string retval;
     char buffer[128];
     do {
-        const size_t n = fread(buffer, 1, sizeof(buffer), f);
+        const size_t n = fread(buffer, 1, std::min(sizeof(buffer), maxsize - retval.size()), f);
         // Check for reading errors so we don't return any data if we couldn't
         // read the entire file (or up to maxsize)
         if (ferror(f)) {
@@ -26,7 +27,7 @@ std::pair<bool,std::string> ReadBinaryFile(const fs::path &filename, size_t maxs
             return std::make_pair(false,"");
         }
         retval.append(buffer, buffer+n);
-    } while (!feof(f) && retval.size() <= maxsize);
+    } while (!feof(f) && retval.size() < maxsize);
     fclose(f);
     return std::make_pair(true,retval);
 }