[TDF] Make TSlotStack helper sturdier against error condtions.
[TDF] Make TSlotStack helper sturdier against error condtions.

zzxuanyuan/root,abhinavmoudgil95/root,agarciamontoro/root,zzxuanyuan/root-compressor-dummy,davidlt/root,beniz/root,root-mirror/root,olifre/root,root-mirror/root,buuck/root,olifre/root,satyarth934/root,BerserkerTroll/root,mhuwiler/rootauto,davidlt/root,agarciamontoro/root,BerserkerTroll/root,karies/root,bbockelm/root,abhinavmoudgil95/root,zzxuanyuan/root-compressor-dummy,agarciamontoro/root,davidlt/root,olifre/root,BerserkerTroll/root,simonpf/root,satyarth934/root,karies/root,BerserkerTroll/root,zzxuanyuan/root,zzxuanyuan/root-compressor-dummy,zzxuanyuan/root,zzxuanyuan/root,zzxuanyuan/root,buuck/root,agarciamontoro/root,simonpf/root,mhuwiler/rootauto,mhuwiler/rootauto,abhinavmoudgil95/root,beniz/root,abhinavmoudgil95/root,simonpf/root,satyarth934/root,bbockelm/root,davidlt/root,abhinavmoudgil95/root,abhinavmoudgil95/root,bbockelm/root,satyarth934/root,simonpf/root,bbockelm/root,bbockelm/root,BerserkerTroll/root,karies/root,zzxuanyuan/root-compressor-dummy,davidlt/root,BerserkerTroll/root,zzxuanyuan/root,agarciamontoro/root,olifre/root,BerserkerTroll/root,root-mirror/root,karies/root,buuck/root,karies/root,simonpf/root,olifre/root,buuck/root,simonpf/root,beniz/root,zzxuanyuan/root,olifre/root,karies/root,davidlt/root,karies/root,zzxuanyuan/root,mhuwiler/rootauto,beniz/root,satyarth934/root,buuck/root,mhuwiler/rootauto,karies/root,beniz/root,mhuwiler/rootauto,root-mirror/root,beniz/root,davidlt/root,BerserkerTroll/root,BerserkerTroll/root,bbockelm/root,olifre/root,buuck/root,agarciamontoro/root,root-mirror/root,olifre/root,simonpf/root,agarciamontoro/root,zzxuanyuan/root-compressor-dummy,abhinavmoudgil95/root,buuck/root,buuck/root,abhinavmoudgil95/root,root-mirror/root,zzxuanyuan/root,simonpf/root,olifre/root,satyarth934/root,BerserkerTroll/root,davidlt/root,agarciamontoro/root,zzxuanyuan/root-compressor-dummy,mhuwiler/rootauto,mhuwiler/rootauto,bbockelm/root,davidlt/root,satyarth934/root,bbockelm/root,beniz/root,abhinavmoudgil95/root,root-mirror/root,simonpf/root,bbockelm/root,bbockelm/root,agarciamontoro/root,satyarth934/root,beniz/root,zzxuanyuan/root-compressor-dummy,abhinavmoudgil95/root,beniz/root,zzxuanyuan/root-compressor-dummy,satyarth934/root,root-mirror/root,zzxuanyuan/root,zzxuanyuan/root-compressor-dummy,olifre/root,simonpf/root,root-mirror/root,root-mirror/root,mhuwiler/rootauto,mhuwiler/rootauto,satyarth934/root,beniz/root,satyarth934/root,karies/root,zzxuanyuan/root-compressor-dummy,BerserkerTroll/root,abhinavmoudgil95/root,olifre/root,bbockelm/root,agarciamontoro/root,buuck/root,buuck/root,buuck/root,beniz/root,zzxuanyuan/root,karies/root,zzxuanyuan/root,simonpf/root,zzxuanyuan/root-compressor-dummy,davidlt/root,davidlt/root,agarciamontoro/root,mhuwiler/rootauto,root-mirror/root,karies/root