merge revision(s) 2bc293e899c9d32dcd794a73de8925c49ecf8f15,d0e6c6e682b9ba2b0309a5177933a0628e8ef316,cc0dc67bbbe1951ff90004bc987f78545625d772,e1eff837cf12a8e813de9d4ff2db50c9b68b86b5,0ab0b86c8491d639b9ff1335ddf35e341ecd867e,6911b4bc82889860ff7da4ecf975504cdc3e5314: [Backport #17854]

	cdhash_cmp: can take rational literals

	Rational literals are those integers suffixed with `r`.  They tend to
	be a part of more complex expressions like `123/456r`, but in theory
	they can live alone.  When such "bare" rational literals are passed to
	case-when branch, we have to take care of them.  Fixes [Bug #17854]
	---
	 common.mk                  |  1 +
	 compile.c                  |  7 +++++++
	 internal/rational.h        |  1 +
	 rational.c                 | 13 ++++++++++---
	 test/ruby/test_rational.rb |  7 +++++++
	 5 files changed, 26 insertions(+), 3 deletions(-)

	cdhash_cmp: rational literals with fractions

	Nobu kindly pointed out that rational literals can have fractions.
	---
	 compile.c                  | 5 +++--
	 test/ruby/test_rational.rb | 4 ++++
	 2 files changed, 7 insertions(+), 2 deletions(-)

	cdhash_cmp: can also take complex

	There are complex literals `123i`, which can also be a case condition.
	---
	 compile.c                  | 15 +++++++++++----
	 complex.c                  | 12 +++++++++---
	 internal/complex.h         |  1 +
	 test/ruby/test_rational.rb |  4 ++++
	 4 files changed, 25 insertions(+), 7 deletions(-)

	cdhash_cmp: recursively apply

	For instance a rational's numerator can be a bignum.  Comparison using
	C's == can be insufficient.
	---
	 compile.c | 4 ++--
	 1 file changed, 2 insertions(+), 2 deletions(-)

	cdhash_cmp: should use ||

	cf: https://github.com/ruby/ruby/pull/4469#discussion_r628386707
	---
	 compile.c | 4 ++--
	 1 file changed, 2 insertions(+), 2 deletions(-)

	test_cdhash: refactor change class

	It is now strange to test Complex in a class named Rational_Test.
	---
	 test/ruby/test_rational.rb | 15 ---------------
	 test/ruby/test_syntax.rb   | 15 +++++++++++++++
	 2 files changed, 15 insertions(+), 15 deletions(-)

1 files changed, 15 insertions, 0 deletions

diff --git a/compile.c b/compile.c
index b78c7f26d9..502d12d6c7 100644
--- a/compile.c
+++ b/compile.c
@@ -28,6 +28,7 @@
 #include "internal/hash.h"
 #include "internal/numeric.h"
 #include "internal/object.h"
+#include "internal/rational.h"
 #include "internal/re.h"
 #include "internal/symbol.h"
 #include "internal/thread.h"
@@ -1985,6 +1986,16 @@ cdhash_cmp(VALUE val, VALUE lit)
     else if (tlit == T_FLOAT) {
         return rb_float_cmp(lit, val);
     }
+    else if (tlit == T_RATIONAL) {
+        const struct RRational *rat1 = RRATIONAL(val);
+        const struct RRational *rat2 = RRATIONAL(lit);
+        return cdhash_cmp(rat1->num, rat2->num) || cdhash_cmp(rat1->den, rat2->den);
+    }
+    else if (tlit == T_COMPLEX) {
+        const struct RComplex *comp1 = RCOMPLEX(val);
+        const struct RComplex *comp2 = RCOMPLEX(lit);
+        return cdhash_cmp(comp1->real, comp2->real) || cdhash_cmp(comp1->imag, comp2->imag);
+    }
     else {
         UNREACHABLE_RETURN(-1);
     }
@@ -2003,6 +2014,10 @@ cdhash_hash(VALUE a)
         return FIX2LONG(rb_big_hash(a));
       case T_FLOAT:
         return rb_dbl_long_hash(RFLOAT_VALUE(a));
+      case T_RATIONAL:
+        return rb_rational_hash(a);
+      case T_COMPLEX:
+        return rb_complex_hash(a);
       default:
         UNREACHABLE_RETURN(0);
     }