Enable int warnings by default

Now that there aren't any more...

ChangeLog

@@ -1,5 +1,10 @@
 2019-06-20  Jay Berkenbilt  <ejb@ql.org>
 
+	* Enable compilation with additional warnings for integer
+	conversion and sign (-Wsign-conversion, -Wconversion for gcc and
+	similar; -W3 for msvc) if supported. These warnings are on by
+	default can be turned off by passing --disable-int-warnings
+
 	* Fix all integer sign and conversion warnings. This makes all
 	integer type conversions that have potential data loss explicit
 	with calls that do range checks and raise an exception.

autofiles.sums

@@ -1,4 +1,4 @@
-585322e3ca6c33acd1d8e3eb3da767c964e93f6fbeb0cf0d2c0cd11bb0b0a445  configure.ac
+1135dabc4af0e846647cd99776813a284a740063e3eb77bcfc327b1cc851b8c0  configure.ac
 35bc5c645dc42d47f2daeea06f8f3e767c8a1aee6a35eb2b4854fd2ce66c3413  m4/ax_random_device.m4
 37f8897d5f68d7d484e5457832a8f190ddb7507fa2a467cb7ee2be40a4364643  m4/libtool.m4
 e77ebba8361b36f14b4d0927173a034b98c5d05049697a9ded84d85eb99a7990  m4/ltoptions.m4

configure

@@ -1440,7 +1440,7 @@ Optional Features:
                           enable linker version script (default is enabled)
   --enable-werror         whether to treat warnings as errors (default is no)
   --enable-int-warnings   whether to turn on integer type warnings (default is
-                          no)
+                          yes)
   --enable-test-compare-images
                           whether to compare images in test suite; disabled by
                           default, enabling requires ghostscript and tiffcmp
@@ -16904,7 +16904,7 @@ if test "${enable_int_warnings+set}" = set; then :
       qpdf_INT_WARNINGS=0;
     fi
 else
-  qpdf_INT_WARNINGS=0
+  qpdf_INT_WARNINGS=1
 fi
 
 if test "$qpdf_INT_WARNINGS" = "1"; then

configure.ac

@@ -396,12 +396,12 @@ fi
 AC_MSG_CHECKING(for whether to use $try_flags)
 AC_ARG_ENABLE(int-warnings,
    AS_HELP_STRING([--enable-int-warnings],
-                  [whether to turn on integer type warnings (default is no)]),
+                  [whether to turn on integer type warnings (default is yes)]),
    [if test "$enableval" = "yes"; then
       qpdf_INT_WARNINGS=1;
     else
       qpdf_INT_WARNINGS=0;
-    fi], [qpdf_INT_WARNINGS=0])
+    fi], [qpdf_INT_WARNINGS=1])
 if test "$qpdf_INT_WARNINGS" = "1"; then
    AC_MSG_RESULT(yes)
    WFLAGS="$WFLAGS $try_flags"