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:187
None	2	2	DGifCloseFile	call site: 00077	/src/giflib-code/dgif_lib.c:707
None	0	72	DGifGetImageHeader	call site: 00024	/src/giflib-code/dgif_lib.c:366
None	0	63	DGifGetImageDesc	call site: 00023	/src/giflib-code/dgif_lib.c:433
None	0	58	DGifGetLine	call site: 00046	/src/giflib-code/dgif_lib.c:487
None	0	58	DGifGetLine	call site: 00046	/src/giflib-code/dgif_lib.c:493
None	0	43	DGifGetScreenDesc	call site: 00007	/src/giflib-code/dgif_lib.c:254
None	0	16	DGifSlurp	call site: 00041	/src/giflib-code/dgif_lib.c:1204
None	0	16	DGifSlurp	call site: 00044	/src/giflib-code/dgif_lib.c:1211
None	0	15	DGifGetExtension	call site: 00062	/src/giflib-code/dgif_lib.c:572
None	0	5	DGifGetRecordType	call site: 00021	/src/giflib-code/dgif_lib.c:329
None	0	0	DGifOpen	call site: 00002	/src/giflib-code/dgif_lib.c:173

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


               DGifDecreaseImageCounter

[function] [call site] 00041


                 openbsd_reallocarray

[function] [call site] 00042


               DGifDecreaseImageCounter

[function] [call site] 00043


               openbsd_reallocarray

[function] [call site] 00044


               DGifDecreaseImageCounter

[function] [call site] 00045


               DGifGetLine

[function] [call site] 00046


                 DGifDecompressLine

[function] [call site] 00047


                   DGifDecompressInput

[function] [call site] 00048


                     DGifBufferedInput

[function] [call site] 00049


                       InternalRead

[function] [call site] 00050


                       InternalRead

[function] [call site] 00051


                   DGifGetPrefixChar

[function] [call site] 00052


                   DGifGetPrefixChar

[function] [call site] 00053


                   DGifGetPrefixChar

[function] [call site] 00054


                   DGifGetPrefixChar

[function] [call site] 00055


                 DGifGetCodeNext

[function] [call site] 00056


                   InternalRead

[function] [call site] 00057


                   InternalRead

[function] [call site] 00058


               DGifDecreaseImageCounter

[function] [call site] 00059


               DGifGetLine

[function] [call site] 00060


               DGifDecreaseImageCounter

[function] [call site] 00061


               DGifGetExtension

[function] [call site] 00062


                 InternalRead

[function] [call site] 00063


                 DGifGetExtensionNext

[function] [call site] 00064


                   InternalRead

[function] [call site] 00065


                   InternalRead

[function] [call site] 00066


               GifAddExtensionBlock

[function] [call site] 00067


                 openbsd_reallocarray

[function] [call site] 00068


               DGifGetExtensionNext

[function] [call site] 00069


               GifAddExtensionBlock

[function] [call site] 00070


             DGifCloseFile

[function] [call site] 00071


               GifFreeMapObject

[function] [call site] 00072


               GifFreeMapObject

[function] [call site] 00073


               GifFreeSavedImages

[function] [call site] 00074


                 GifFreeMapObject

[function] [call site] 00075


                 GifFreeExtensions

[function] [call site] 00076


               GifFreeExtensions

[function] [call site] 00077


               fclose

[call site] 00078


             DGifSavedExtensionToGCB

[function] [call site] 00079


               DGifExtensionToGCB

[function] [call site] 00080


             DGifSavedExtensionToGCB

[function] [call site] 00081


             DGifCloseFile

[function] [call site] 00082