Remove abs calls and pick correct floating point epsilon values (fixes #641)

Jay Berkenbilt
1 parent 4ff837f0
Showing 3 changed files with 9 additions and 4 deletions
README-maintainer
qpdf/qpdf-ctest.c
qpdf/test_driver.cc
@@ -98,6 +98,11 @@ CODING RULES
 * Avoid atoi. Use QUtil::string_to_int instead. It does
   overflow/underflow checking.
  
+* Avoid certain functions that tend to be macros or create compilation
+  errors on some platforms. Known cases: strcasecmp, abs. Avoid min
+  and max. If needed, std::min and std::max are okay to use in C++
+  code with <algorithm> included.
+
 * Remember to avoid using `operator[]` with `std::string` or
   `std::vector`. Instead, use `at()`. See README-hardening.md for
   details.
@@ -714,7 +714,7 @@ static void test25(char const* infile,
     double d = 0.0;
     assert(qpdf_oh_get_value_as_number(qpdf, p_bool, &d) == QPDF_FALSE);
     assert((qpdf_oh_get_value_as_number(qpdf, p_int, &d) == QPDF_TRUE) &&
-            (((d - 1.0) * (d - 1.0)) < 1e-100));
+           ((d - 1.0) < 1e-6) && ((d - 1.0) > -1e-6));
     assert(qpdf_oh_get_type_code(qpdf, p_int) == ot_integer);
     assert(strcmp(qpdf_oh_get_type_name(qpdf, p_int), "integer") == 0);
     assert(qpdf_oh_is_real(qpdf, p_real) &&
@@ -3293,11 +3293,11 @@ static void test_85(QPDF&amp; pdf, char const* arg2)
     assert(s == "42.0");
     double num = 0.0;
     assert(oh_i.getValueAsNumber(num));
-    assert(abs(num - 1.0) < 1e-100);
+    assert(((num - 1.0) < 1e-6) && (num - 1.0 > -1e-6));
     assert(oh_r.getValueAsNumber(num));
-    assert(abs(num - 42.0) < 1e-100);
+    assert(((num - 42.0) < 1e-6) && (num - 42.0 > -1e-6));
     assert(! oh_b.getValueAsNumber(num));
-    assert(abs(num - 42.0) < 1e-100);
+    assert(((num - 42.0) < 1e-6) && (num - 42.0 > -1e-6));
     s = "";
     assert(oh_n.getValueAsName(s));
     assert(s == "/Test") ;