t/op/sprintf2.t - append new test (Issue 18170)

diff --git a/t/op/sprintf2.t b/t/op/sprintf2.t
index 38a550c..b1996e7 100644 (file)
--- a/t/op/sprintf2.t
+++ b/t/op/sprintf2.t
@@ -1178,4 +1178,44 @@ if ($Config{intsize} == 4 && $Config{uvsize} > 4 && $Config{sizesize} > 4) {
     is($off2, 1, "offset after 0");
 }
 
+# %g formatting was broken on Ubuntu, Debian and perhaps other systems
+# for a long time. Here we verify that no such breakage still exists.
+# See https://github.com/Perl/perl5/issues/18170
+
+if($Config{nvsize} == 8) {
+    # double or 8-byte long double
+    TODO: {
+        local $::TODO = 'Extended precision %g formatting' if $^O eq 'cygwin'
+                                   or
+                               ($^O eq 'MSWin32' and
+                                $Config{cc} eq 'cl' and
+                                $Config{ccversion} =~ /^(\d+)/ and
+                                $1 < 19);
+
+        cmp_ok(sprintf("%.54g", 0.3), 'eq', '0.299999999999999988897769753748434595763683319091796875',
+               "sprintf( \"%.54g\", 0.3 ) renders correctly");
+    }
+}
+elsif($Config{nvtype} eq 'long double' && ($Config{longdblkind} == 3 || $Config{longdblkind} == 4)) {
+    # 80-bit extended precision long double
+    TODO: {
+        local $::TODO = 'Extended precision %g formatting' if $^O eq 'cygwin';
+
+        cmp_ok(sprintf("%.64g", 0.3), 'eq', '0.3000000000000000000108420217248550443400745280086994171142578125',
+              "sprintf( \"%.64g\", 0.3 ) renders correctly");
+    }
+}
+elsif($Config{nvtype} eq 'long double' && $Config{longdblkind} >= 5 && $Config{longdblkind} <= 8) {
+    # double-double
+    cmp_ok(sprintf("%.108g", 0.1), 'eq',
+           '0.0999999999999999999999999999999996918512088980422635110435291864116290339037362855378887616097927093505859375',
+           "sprintf( \"%.108g\", 0.1 ) renders correctly");
+}
+else {
+    # IEEE-754 128-bit long double or __float128
+    cmp_ok(sprintf("%.115g", 0.3), 'eq',
+           '0.299999999999999999999999999999999990370350278063820734720110287075363407309491758923059023800306022167205810546875',
+           "sprintf( \"%.115g\", 0.3 ) renders correctly");
+}
+
 done_testing();