Fuzz blockers

The followings are the branches where fuzzer fails to bypass.

Unique Reachable Functions	All non-covered Complexity	All Reachable Complexity	Function Name	Function Callsite	Blocked Branch
None	2	39	DGifOpen	call site: 00003	/src/giflib-code/dgif_lib.c:185
None	2	2	DGifCloseFile	call site: 00071	/src/giflib-code/dgif_lib.c:699
None	0	72	DGifGetImageHeader	call site: 00024	/src/giflib-code/dgif_lib.c:365
None	0	63	DGifGetImageDesc	call site: 00023	/src/giflib-code/dgif_lib.c:432
None	0	58	DGifGetLine	call site: 00042	/src/giflib-code/dgif_lib.c:488
None	0	58	DGifGetLine	call site: 00042	/src/giflib-code/dgif_lib.c:494
None	0	43	DGifGetScreenDesc	call site: 00007	/src/giflib-code/dgif_lib.c:249
None	0	15	DGifGetExtension	call site: 00056	/src/giflib-code/dgif_lib.c:570
None	0	5	DGifGetRecordType	call site: 00021	/src/giflib-code/dgif_lib.c:326
None	0	0	DGifOpen	call site: 00002	/src/giflib-code/dgif_lib.c:172
None	0	0	DGifGetScreenDesc	call site: 00013	/src/giflib-code/dgif_lib.c:275
None	0	0	DGifGetImageHeader	call site: 00032	/src/giflib-code/dgif_lib.c:395

Fuzzer calltree


         LLVMFuzzerTestOneInput

[function] [call site] 00000


           fuzz_dgif_extended(unsigned char const*, unsigned long)

[function] [call site] 00001


             DGifOpen

[function] [call site] 00002


               calloc

[call site] 00003


               InternalRead

[function] [call site] 00004


                 fread

[call site] 00005


               strncmp

[call site] 00006


               DGifGetScreenDesc

[function] [call site] 00007


                 DGifGetWord

[function] [call site] 00008


                   InternalRead

[function] [call site] 00009


                 DGifGetWord

[function] [call site] 00010


                 InternalRead

[function] [call site] 00011


                 GifFreeMapObject

[function] [call site] 00012


                 GifMakeMapObject

[function] [call site] 00013


                   GifBitSize

[function] [call site] 00014


                   calloc

[call site] 00015


                   GifBitSize

[function] [call site] 00016


                 InternalRead

[function] [call site] 00017


                 GifFreeMapObject

[function] [call site] 00018


             stub_input_reader(GifFileType*, unsigned char*, int)

[function] [call site] 00019


             DGifSlurp

[function] [call site] 00020


               DGifGetRecordType

[function] [call site] 00021


                 InternalRead

[function] [call site] 00022


               DGifGetImageDesc

[function] [call site] 00023


                 DGifGetImageHeader

[function] [call site] 00024


                   DGifGetWord

[function] [call site] 00025


                   DGifGetWord

[function] [call site] 00026


                   DGifGetWord

[function] [call site] 00027


                   DGifGetWord

[function] [call site] 00028


                   InternalRead

[function] [call site] 00029


                   GifFreeMapObject

[function] [call site] 00030


                   GifFreeMapObject

[function] [call site] 00031


                   GifMakeMapObject

[function] [call site] 00032


                   InternalRead

[function] [call site] 00033


                   GifFreeMapObject

[function] [call site] 00034


                   DGifSetupDecompress

[function] [call site] 00035


                     InternalRead

[function] [call site] 00036


                 openbsd_reallocarray

[function] [call site] 00037


                   __errno_location

[call site] 00038


                   realloc

[call site] 00039


                 GifMakeMapObject

[function] [call site] 00040


               openbsd_reallocarray

[function] [call site] 00041


               DGifGetLine

[function] [call site] 00042


                 DGifDecompressLine

[function] [call site] 00043


                   DGifDecompressInput

[function] [call site] 00044


                     DGifBufferedInput

[function] [call site] 00045


                       InternalRead

[function] [call site] 00046


                       InternalRead

[function] [call site] 00047


                   DGifGetPrefixChar

[function] [call site] 00048


                   DGifGetPrefixChar

[function] [call site] 00049


                   DGifGetPrefixChar

[function] [call site] 00050


                   DGifGetPrefixChar

[function] [call site] 00051


                 DGifGetCodeNext

[function] [call site] 00052


                   InternalRead

[function] [call site] 00053


                   InternalRead

[function] [call site] 00054


               DGifGetLine

[function] [call site] 00055


               DGifGetExtension

[function] [call site] 00056


                 InternalRead

[function] [call site] 00057


                 DGifGetExtensionNext

[function] [call site] 00058


                   InternalRead

[function] [call site] 00059


                   InternalRead

[function] [call site] 00060


               GifAddExtensionBlock

[function] [call site] 00061


                 openbsd_reallocarray

[function] [call site] 00062


               DGifGetExtensionNext

[function] [call site] 00063


               GifAddExtensionBlock

[function] [call site] 00064


             DGifCloseFile

[function] [call site] 00065


               GifFreeMapObject

[function] [call site] 00066


               GifFreeMapObject

[function] [call site] 00067


               GifFreeSavedImages

[function] [call site] 00068


                 GifFreeMapObject

[function] [call site] 00069


                 GifFreeExtensions

[function] [call site] 00070


               GifFreeExtensions

[function] [call site] 00071


               fclose

[call site] 00072


             DGifSavedExtensionToGCB

[function] [call site] 00073


               DGifExtensionToGCB

[function] [call site] 00074


             DGifSavedExtensionToGCB

[function] [call site] 00075


             DGifCloseFile

[function] [call site] 00076