Bug 390386

Kdenlive crashes when opening a specified mkv file.

What was expected to happen was:
Kdenlive adds the mkv once to the project bin.

What actually happened was:
Kdenlive was repeating adding the mkv to the project bin.
The whole process is captured at "http://klsztx.nos-eastchina1.126.net/Kdenlive.webm" (2.0MiB, VP8/WebM, 00:00:22).

Steps to reproduce:
Download the mkv file from "http://klsztx.nos-eastchina1.126.net/Kdenlive.mkv" (186.0MiB, H264_Hi10P/FLAC/mkv, 00:01:31) and open it in your kdenlive.

More informations:
1. only THE mkv file will cause the problem; other mkvs don't.
2. log from terminal is as follows.
3. the mkv info from MKVToolNix is as follows.

log
```
OpenGL vendor:  "Intel Open Source Technology Center"
OpenGL renderer:  "Mesa DRI Intel(R) Haswell Mobile "
OpenGL Threaded:  false
OpenGL ARG_SYNC:  true
OpenGL OpenGLES:  false
OpenGL vendor:  "Intel Open Source Technology Center"
OpenGL renderer:  "Mesa DRI Intel(R) Haswell Mobile "
OpenGL Threaded:  false
OpenGL ARG_SYNC:  true
OpenGL OpenGLES:  false
QXcbConnection: XCB error: 8 (BadMatch), sequence: 635, resource id: 71303191, major code: 155 (Unknown), minor code: 11
kf5.kio.core: Refilling KProtocolInfoFactory cache in the hope to find "mtp"
KServiceTypeTrader: serviceType "ThumbCreator" not found
KServiceTypeTrader: serviceType "ThumbCreator" not found
KSambaShare: Could not find smb.conf!
KServiceTypeTrader: serviceType "ThumbCreator" not found
KServiceTypeTrader: serviceType "ThumbCreator" not found
[swscaler @ 0x7f6560b88a60] Warning: data is not aligned! This can lead to a speedloss
* * *CREATED PROD:  "/home/klsz/kdenlive/[philosophy-raws][EF - a Tale of Memories][NCOP][BDRIP][Hi10P FLAC][1920X1080].mkv"  =  "/home/klsz/kdenlive/[philosophy-raws][EF - a Tale of Memories][NCOP][BDRIP][Hi10P FLAC][1920X1080].mkv"
* * *CREATED PROD:  "/home/klsz/kdenlive/[philosophy-raws][EF - a Tale of Memories][NCOP][BDRIP][Hi10P FLAC][1920X1080].mkv"  =  "/home/klsz/kdenlive/[philosophy-raws][EF - a Tale of Memories][NCOP][BDRIP][Hi10P FLAC][1920X1080].mkv"
* * *CREATED PROD:  "/home/klsz/kdenlive/[philosophy-raws][EF - a Tale of Memories][NCOP][BDRIP][Hi10P FLAC][1920X1080].mkv"  =  "/home/klsz/kdenlive/[philosophy-raws][EF - a Tale of Memories][NCOP][BDRIP][Hi10P FLAC][1920X1080].mkv"
* * *CREATED PROD:  "/home/klsz/kdenlive/[philosophy-raws][EF - a Tale of Memories][NCOP][BDRIP][Hi10P FLAC][1920X1080].mkv"  =  "/home/klsz/kdenlive/[philosophy-raws][EF - a Tale of Memories][NCOP][BDRIP][Hi10P FLAC][1920X1080].mkv"
* * *CREATED PROD:  "/home/klsz/kdenlive/[philosophy-raws][EF - a Tale of Memories][NCOP][BDRIP][Hi10P FLAC][1920X1080].mkv"  =  "/home/klsz/kdenlive/[philosophy-raws][EF - a Tale of Memories][NCOP][BDRIP][Hi10P FLAC][1920X1080].mkv"
"Creating audio thumbnails"
* * *CREATED PROD:  "/home/klsz/kdenlive/[philosophy-raws][EF - a Tale of Memories][NCOP][BDRIP][Hi10P FLAC][1920X1080].mkv"  =  "/home/klsz/kdenlive/[philosophy-raws][EF - a Tale of Memories][NCOP][BDRIP][Hi10P FLAC][1920X1080].mkv"
```
Then it repeated the line "* * *CREAT...1080].mkv"" above again and again until I quitted kdenlive.

mkvinfo
```
+ EBML head
|+ EBML version: 1
|+ EBML read version: 1
|+ EBML maximum ID length: 4
|+ EBML maximum size length: 8
|+ Doc type: matroska
|+ Doc type version: 4
|+ Doc type read version: 2
+ Segment, size 195020325
|+ Seek head
| + Seek entry
|  + Seek ID: 0x15 0x49 0xa9 0x66 (KaxInfo)
|  + Seek position: 4099
| + Seek entry
|  + Seek ID: 0x16 0x54 0xae 0x6b (KaxTracks)
|  + Seek position: 4257
| + Seek entry
|  + Seek ID: 0x1c 0x53 0xbb 0x6b (KaxCues)
|  + Seek position: 195019835
|+ EbmlVoid (size: 4044)
|+ Segment information
| + Timecode scale: 1000000
| + Multiplexing application: libebml v1.3.0 + libmatroska v1.4.0
| + Writing application: mkvmerge v5.8.0 ('No Sleep / Pillow') built on Sep 30 2012 10:57:14
| + Duration: 91.091s (00:01:31.091)
| + Date: Thu Jan 01 00:00:02 1970 UTC
| + Segment UID: 0x9c 0x7a 0x4b 0x59 0x2f 0xa2 0x30 0x7b 0x8c 0x32 0x06 0x88 0xd4 0x3b 0x0e 0x03
|+ Segment tracks
| + A track
|  + Track number: 1 (track ID for mkvmerge & mkvextract: 0)
|  + Track UID: 10550483950929503638
|  + Track type: audio
|  + Codec ID: A_FLAC
|  + CodecPrivate, length 8282
|  + Default duration: 85.333ms (11.719 frames/fields per second for a video track)
|  + Language: und
|  + Audio track
|   + Sampling frequency: 48000
|   + Channels: 2
|   + Bit depth: 16
| + A track
|  + Track number: 2 (track ID for mkvmerge & mkvextract: 1)
|  + Track UID: 13346415731965218970
|  + Track type: audio
|  + Default flag: 0
|  + Codec ID: A_FLAC
|  + CodecPrivate, length 8282
|  + Default duration: 85.333ms (11.719 frames/fields per second for a video track)
|  + Language: und
|  + Audio track
|   + Sampling frequency: 48000
|   + Channels: 2
|   + Bit depth: 16
| + A track
|  + Track number: 3 (track ID for mkvmerge & mkvextract: 2)
|  + Track UID: 1
|  + Track type: video
|  + Lacing flag: 0
|  + MinCache: 1
|  + Codec ID: V_MPEG4/ISO/AVC
|  + CodecPrivate, length 50 (h.264 profile: High 10 @L5.0)
|  + Default duration: 41.708ms (23.976 frames/fields per second for a video track)
|  + Video track
|   + Pixel width: 1920
|   + Pixel height: 1080
|   + Display width: 1920
|   + Display height: 1080
|  + Content encodings
|   + Content encoding
|    + Content compression
|     + Algorithm: 3 (header removal)
|     + Settings: length 1, data: 0x00
| + A track
|  + Track number: 4 (track ID for mkvmerge & mkvextract: 3)
|  + Track UID: 1487549536289931399
|  + Track type: video
|  + Default flag: 0
|  + Lacing flag: 0
|  + MinCache: 1
|  + Codec ID: V_MPEG4/ISO/AVC
|  + CodecPrivate, length 50 (h.264 profile: High 10 @L5.0)
|  + Default duration: 41.708ms (23.976 frames/fields per second for a video track)
|  + Video track
|   + Pixel width: 1920
|   + Pixel height: 1080
|   + Display width: 1920
|   + Display height: 1080
|  + Content encodings
|   + Content encoding
|    + Content compression
|     + Algorithm: 3 (header removal)
|     + Settings: length 1, data: 0x00
| + A track
|  + Track number: 5 (track ID for mkvmerge & mkvextract: 4)
|  + Track UID: 11897267384732250520
|  + Track type: video
|  + Default flag: 0
|  + Lacing flag: 0
|  + MinCache: 1
|  + Codec ID: V_MPEG4/ISO/AVC
|  + CodecPrivate, length 50 (h.264 profile: High 10 @L5.0)
|  + Default duration: 41.708ms (23.976 frames/fields per second for a video track)
|  + Video track
|   + Pixel width: 1920
|   + Pixel height: 1080
|   + Display width: 1920
|   + Display height: 1080
|  + Content encodings
|   + Content encoding
|    + Content compression
|     + Algorithm: 3 (header removal)
|     + Settings: length 1, data: 0x00
|+ EbmlVoid (size: 1220)
|+ Cluster
```