Be more careful with fread in various places.

[dcpomatic.git] / src / lib / util.cc

diff --git a/src/lib/util.cc b/src/lib/util.cc
index 051a4bb25ec9e0b84fe6aa0d890ed4bf6f88f469..5eba8d73a0f214f07339998c9a6c4543f5f86e2f 100644 (file)
--- a/src/lib/util.cc
+++ b/src/lib/util.cc
@@ -444,7 +444,7 @@ digest_head_tail (vector<boost::filesystem::path> files, boost::uintmax_t size)
                }
 
                boost::uintmax_t this_time = min (to_do, boost::filesystem::file_size (files[i]));
-               fread (p, 1, this_time, f);
+               checked_fread (p, this_time, f, files[i]);
                p += this_time;
                to_do -= this_time;
                fclose (f);
@@ -465,7 +465,7 @@ digest_head_tail (vector<boost::filesystem::path> files, boost::uintmax_t size)
 
                boost::uintmax_t this_time = min (to_do, boost::filesystem::file_size (files[i]));
                dcpomatic_fseek (f, -this_time, SEEK_END);
-               fread (p, 1, this_time, f);
+               checked_fread (p, this_time, f, files[i]);
                p += this_time;
                to_do -= this_time;
                fclose (f);
@@ -782,3 +782,16 @@ increment_eyes (Eyes e)
 
        return EYES_LEFT;
 }
+
+void
+checked_fread (void* ptr, size_t size, FILE* stream, boost::filesystem::path path)
+{
+       size_t N = fread (ptr, 1, size, stream);
+       if (N != size) {
+               if (ferror(stream)) {
+                       throw FileError (String::compose("fread error %1", errno), path);
+               } else {
+                       throw FileError ("Unexpected short read", path);
+               }
+       }
+}