CLZSS::SafeUncompress

/* CLZSS::SafeUncompress(unsigned char*, unsigned int, unsigned char*, unsigned int) */

uint __thiscall
CLZSS::SafeUncompress(CLZSS *this,uchar *param_1,uint param_2,uchar *param_3,uint param_4)

{
  int iVar1;
  byte bVar2;
  uint uVar3;
  uint uVar4;
  int iVar5;
  byte *pbVar6;
  uint uVar7;
  byte *pbVar8;
  uint uVar9;
  uint local_20;
  uint local_1c;
  int local_18;
  
  if ((((param_2 < 9) || (param_1 == (uchar *)0x0)) || (*(int *)param_1 != 0x53535a4c)) ||
     ((uVar3 = *(uint *)(param_1 + 4), uVar3 == 0 || (param_4 < uVar3)))) {
    return 0;
  }
  pbVar8 = param_1 + 8;
  uVar9 = 0;
  local_1c = 0;
  local_20 = 0;
  local_18 = param_2 - 8;
  do {
    if (uVar9 == 0) {
      if (local_18 == 0) {
        return 0;
      }
      local_1c = (uint)*pbVar8;
      pbVar8 = pbVar8 + 1;
      local_18 = local_18 + -1;
    }
    uVar9 = uVar9 + 1 & 7;
    if ((local_1c & 1) == 0) {
      local_20 = local_20 + 1;
      if (param_4 < local_20) {
        return 0;
      }
      if (local_18 == 0) {
        return 0;
      }
      bVar2 = *pbVar8;
      pbVar6 = param_3 + 1;
      pbVar8 = pbVar8 + 1;
      local_18 = local_18 + -1;
      *param_3 = bVar2;
    }
    else {
      if (local_18 == 0) {
        return 0;
      }
      bVar2 = *pbVar8;
      if (local_18 == 1) {
        return 0;
      }
      pbVar6 = pbVar8 + 1;
      pbVar8 = pbVar8 + 2;
      local_18 = local_18 + -2;
      uVar7 = *pbVar6 & 0xf;
      uVar4 = (int)(uint)*pbVar6 >> 4 | (uint)bVar2 << 4;
      iVar1 = uVar7 + 1;
      if (iVar1 == 1) {
        if (local_20 == uVar3) {
          return local_20;
        }
        return 0;
      }
      if (local_20 <= uVar4) {
        return 0;
      }
      local_20 = local_20 + iVar1;
      if (param_4 < local_20) {
        return 0;
      }
      iVar5 = 0;
      do {
        param_3[iVar5] = param_3[iVar5 + ~uVar4];
        iVar5 = iVar5 + 1;
      } while (iVar5 < iVar1);
      pbVar6 = param_3 + uVar7 + 1;
    }
    local_1c = (int)local_1c >> 1;
    param_3 = pbVar6;
  } while( true );
}