[Boost-bugs] [Boost C++ Libraries] #11314: boost::gil::jpeg_read_dimensions(const char*) does not throw exceptions as it should

Subject: [Boost-bugs] [Boost C++ Libraries] #11314: boost::gil::jpeg_read_dimensions(const char*) does not throw exceptions as it should
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2015-05-17 16:01:38

#11314: boost::gil::jpeg_read_dimensions(const char*) does not throw exceptions as
it should
------------------------------+---------------------
 Reporter:  anonymous         |      Owner:  hljin
     Type:  Bugs              |     Status:  new
Milestone:  To Be Determined  |  Component:  GIL
  Version:  Boost 1.58.0      |   Severity:  Problem
 Keywords:  libjpeg           |
------------------------------+---------------------
 boost::gil::jpeg_read_dimensions(const char*) is documented as followed
 (resides in .../boost/gil/extension/io/jpeg_io.hpp):

 {{{
 /// \ingroup JPEG_IO
 /// \brief Returns the width and height of the JPEG file at the specified
 location.
 /// Throws std::ios_base::failure if the location does not correspond to a
 valid JPEG file
 }}}

 However, it does not always throw an exception. Instead it prints an error
 message and exits the program, which is how libjpeg by default handle its
 errors.

 See the following code:

 {{{
 #include <iostream>

 #include <boost/gil/extension/io/jpeg_io.hpp>

 using std::cout;
 using std::cerr;
 using std::endl;
 using std::ios_base;

 namespace gil = boost::gil;

 int main(int argc, char **argv) {
   if(argc != 2) {
     cerr << "Please supply a file name." << endl;
     return 1;
   }

   const char *file = argv[1];

   cout << file << ": " << endl;

   try {
     gil::jpeg_read_dimensions(file);
   } catch(const ios_base::failure &ib_f) {
     cerr << "what: " << ib_f.what() << endl;
   } catch(...) {
     cerr << "caught other exception!" << endl;
   }

   cout << "\nDone." << endl;

   return 0;
 }
 }}}

 I compile it using g++ 4.9.2 using the options

 {{{
 -std=c++11 -I/usr/local/include -L/usr/local/lib -ljpeg -o bin main.cpp
 }}}

 on a Mac OS X 10.9.5.

 See these three runs:

 {{{
 $ ./bin non_existing.jpeg # this file does not exist
 non_existing.jpeg:
 what: file_mgr: failed to open file

 Done.
 }}}

 {{{
 $ ./bin existing_empty.jpeg # this file exist but is empty
 existing_empty.jpeg:
 Empty input file
 }}}

 {{{
 $ ./bin existing_non_jpeg.jpeg # this file exist and is not empty, but is
 not a jpeg
 existing_non_jpeg.jpeg:
 Not a JPEG file: starts with 0x62 0x6c
 }}}

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/11314>
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