Change zlib_error to take message and code

2 files changed, 8 insertions, 5 deletions

diff --git a/include/io/zlib_error.h b/include/io/zlib_error.h
index 12eaf20a3f..ce375a6ccd 100644
--- a/include/io/zlib_error.h
+++ b/include/io/zlib_error.h
@@ -2,6 +2,7 @@
 #define ZLIB_ERROR_H_INCLUDED
 
 #include <stdexcept>
+#include <zlib.h>
 
 ///Exception thrown in case zlib encounters a problem
 class zlib_error : public std::runtime_error
@@ -9,8 +10,9 @@ class zlib_error : public std::runtime_error
 public:
     const int errcode;
 
-    explicit zlib_error(const char* what_arg, int errcode = -1):
-        std::runtime_error(what_arg), errcode(errcode)
+    explicit zlib_error(const char* msg, int errcode):
+        std::runtime_error(std::string(zError(errcode)) + ": " + msg),
+        errcode(errcode)
     {}
 };
 
diff --git a/src/io/izlibstream.cpp b/src/io/izlibstream.cpp
index 9079489507..f9d9463d95 100644
--- a/src/io/izlibstream.cpp
+++ b/src/io/izlibstream.cpp
@@ -33,7 +33,7 @@ inflate_streambuf::inflate_streambuf(std::istream& input, size_t bufsize, int wi
     zstr.avail_in = 0;
     int ret = inflateInit2(&zstr, window_bits);
     if(ret != Z_OK)
-        throw zlib_error("inflateInit failed", ret);
+        throw zlib_error(zstr.msg, ret);
 
     char* end = out.data() + out.size();
     setg(end, end, end);
@@ -70,15 +70,16 @@ inflate_streambuf::int_type inflate_streambuf::underflow()
         {
         case Z_NEED_DICT:
         case Z_DATA_ERROR:
-            throw zlib_error("Error decompressing data", ret);
+            throw zlib_error(zstr.msg, ret);
+
         case Z_MEM_ERROR:
             throw std::bad_alloc();
+
         case Z_STREAM_END:
             if(have == 0)
                 return traits_type::eof();
             break;
         }
-
     } while(have == 0);
 
     setg(out.data(), out.data(), out.data() + have);