
Attach (recommended) or Link to PDF file here:
[NAPEN16171380959.pdf](https://github.com/mozilla/pdf.js/files/6143802/NAPEN16171380959.pdf)

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- Operating system and its version: Windows 10
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++ifLevel;
          } else if (op === 0x1b) {
            
            inELSE = ifLevel;
          } else if (op === 0x59) {
            
            if (inELSE === ifLevel) {
              inELSE = 0;
            }
            --ifLevel;
          } else if (op === 0x1c) {
            
            if (!inFDEF && !inELSE) {
              var offset = stack[stack.length - 1];
              
              if (offset > 0) {
                i += offset - 1;
              }
            }
          }
          
          if (!inFDEF && !inELSE) {
            let stackDelta = 0;
            if (op <= 0x8e) {
              stackDelta = TTOpsStackDeltas[op];
            } else if (op >= 0xc0 && op <= 0xdf) {
              stackDelta = -1;
            } else if (op >= 0xe0) {
              stackDelta = -2;
            }