Exempi crashes on some WEBP files:

> $ printf 'RIFFxxxxWEBP' > bad-free.webp
> $ exempi -x bad-free.webp
> processing file bad-free.webp
> dump_xmp for file bad-free.webp
> Segmentation fault

Backtrace:

> #0  0xb7edb5d5 in WEBP_MetaHandler::~WEBP_MetaHandler (this=0x8000fe28, __in_chrg=<optimized out>) at WEBP_Handler.cpp:70
> #1  0xb7edb63a in WEBP_MetaHandler::~WEBP_MetaHandler (this=0x8000fe28, __in_chrg=<optimized out>) at WEBP_Handler.cpp:72
> #2  0xb7e93577 in DoOpenFile (thiz=thiz@entry=0x80014170, clientIO=clientIO@entry=0x0, clientPath=clientPath@entry=0xbffff801 "bad-free.webp", format=<optimized out>, openFlags=<optimized out>) at XMPFiles.cpp:1078
> #3  0xb7e950a7 in XMPFiles::OpenFile (this=0x80014170, clientPath=0xbffff801 "bad-free.webp", format=538976288, openFlags=1) at XMPFiles.cpp:1179
> #4  0xb7e91278 in WXMPFiles_OpenFile_1 (xmpObjRef=<optimized out>, filePath=<optimized out>, format=<optimized out>, openFlags=<optimized out>, wResult=<optimized out>) at WXMPFiles.cpp:233
> #5  0xb7e44cc6 in TXMPFiles<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >::OpenFile (this=0x8000ff10, filePath=0xbffff801 "bad-free.webp", format=538976288, openFlags=1) at ../public/include/client-glue/TXMPFiles.incl_cpp:313
> #6  0xb7e3c76a in xmp_files_open_new (path=0xbffff801 "bad-free.webp", options=XMP_OPEN_READ) at exempi.cpp:281
> #7  0x800022c4 in get_xmp_from_file (filename=0xbffff801 "bad-free.webp", no_reconcile=<optimized out>, is_an_xmp=<optimized out>) at main.cpp:235
> #8  0x800017cb in dump_xmp (outio=<optimized out>, is_an_xmp=<optimized out>, no_reconcile=<optimized out>, filename=0xbffff801 "bad-free.webp") at main.cpp:250
> #9  process_file (output="", prop_value="", value_name="", action=<optimized out>, dump_xml=<optimized out>, write_in_place=<optimized out>, is_an_xmp=<optimized out>, no_reconcile=<optimized out>, filename=0xbffff801 "bad-free.webp") at main.cpp:340

AIUI, this happens because the WEBP_MetaHandler class doesn't initialize the psirMgr and iptcMgr members, but it tries to delete them in the destructor.

Tested with git master (b1859382628b5ba961548980e3b0725d6f934b20).

Found using American Fuzzy Lop:
http://lcamtuf.coredump.cx/afl/

Fixed in the 2.4.x branch at 7ab1ed70f72a1ccb257b2be264b3ed0c00a6f1d7

Thanks for the report.