OpenSystemsDevelopment / qpdf

Commit 727d14cb43106b252fae92c4c30e4b85a4f6d7d0

Authored by m-holger
1 parent 7a23bfb6

Refactor `validatePDFVersion` and `findHeader`: simplify logic, improve readabil… 

…ity, and replace deprecated API usage.
Inline Side-by-side
Showing 1 changed file with 26 additions and 27 deletions
libqpdf/QPDF.cc
  View file @727d14c
... ... @@ -366,21 +366,20 @@ QPDF::numWarnings() const
366 366 bool
367 367 QPDF::validatePDFVersion(char const*& p, std::string& version)
368 368 {
369   - bool valid = util::is_digit(*p);
370   - if (valid) {
371   - while (util::is_digit(*p)) {
372   - version.append(1, *p++);
373   - }
374   - if ((*p == '.') && util::is_digit(*(p + 1))) {
375   - version.append(1, *p++);
376   - while (util::is_digit(*p)) {
377   - version.append(1, *p++);
378   - }
379   - } else {
380   - valid = false;
381   - }
  369 + if (!util::is_digit(*p)) {
  370 + return false;
  371 + }
  372 + while (util::is_digit(*p)) {
  373 + version.append(1, *p++);
382 374 }
383   - return valid;
  375 + if (!(*p == '.' && util::is_digit(*(p + 1)))) {
  376 + return false;
  377 + }
  378 + version.append(1, *p++);
  379 + while (util::is_digit(*p)) {
  380 + version.append(1, *p++);
  381 + }
  382 + return true;
384 383 }
385 384  
386 385 bool
... ... @@ -388,26 +387,26 @@ QPDF::findHeader()
388 387 {
389 388 qpdf_offset_t global_offset = m->file->tell();
390 389 std::string line = m->file->readLine(1024);
391   - char const* p = line.c_str();
  390 + char const* p = line.data();
392 391 if (strncmp(p, "%PDF-", 5) != 0) {
393 392 throw std::logic_error("findHeader is not looking at %PDF-");
394 393 }
395 394 p += 5;
396 395 std::string version;
397   - // Note: The string returned by line.c_str() is always null-terminated. The code below never
  396 + // Note: The string returned by line.data() is always null-terminated. The code below never
398 397 // overruns the buffer because a null character always short-circuits further advancement.
399   - bool valid = validatePDFVersion(p, version);
400   - if (valid) {
401   - m->pdf_version = version;
402   - if (global_offset != 0) {
403   - // Empirical evidence strongly suggests that when there is leading material prior to the
404   - // PDF header, all explicit offsets in the file are such that 0 points to the beginning
405   - // of the header.
406   - QTC::TC("qpdf", "QPDF global offset");
407   - m->file = std::shared_ptr<InputSource>(new OffsetInputSource(m->file, global_offset));
408   - }
  398 + if (!validatePDFVersion(p, version)) {
  399 + return false;
  400 + }
  401 + m->pdf_version = version;
  402 + if (global_offset != 0) {
  403 + // Empirical evidence strongly suggests (codified in PDF 2.0 spec) that when there is
  404 + // leading material prior to the PDF header, all explicit offsets in the file are such that
  405 + // 0 points to the beginning of the header.
  406 + QTC::TC("qpdf", "QPDF global offset");
  407 + m->file = std::make_shared<OffsetInputSource>(m->file, global_offset);
409 408 }
410   - return valid;
  409 + return true;
411 410 }
412 411  
413 412 void
... ...