Merge commit r32996 from trunk:

* ext/bigdecimal/bigdecimal.c (cannot_be_coerced_into_BigDecimal):
      add a new function for raising error when an object cannot coerce
      into BigDecimal.  [Bug #5172]
    * ext/bigdecimal/bigdecimal.c (BigDecimalValueWithPrec): use
      cannot_be_coerced_into_BigDecimal function.
    * ext/bigdecimal/bigdecimal.c (BigMath_s_exp): ditto.
    * ext/bigdecimal/bigdecimal.c (BigMath_s_log): ditto.
    * test/bigdecimal/test_bigdecimal.rb: test for the avobe changes.
    * test/bigdecimal/testbase.rb (under_gc_stress): add a new utility
      method to run tests under the condition of GC.stress = true.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_3@32997 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

test/bigdecimal/test_bigdecimal.rb

@@ -1086,7 +1086,7 @@ class TestBigDecimal < Test::Unit::TestCase
     assert_equal(BigDecimal::SIGN_NEGATIVE_ZERO, BigDecimal.new("-1E-1" + "0" * 10000).sign)
   end
 
-  def test_gc
+  def test_split_under_gc_stress
     bug3258 = '[ruby-dev:41213]'
     stress, GC.stress = GC.stress, true
     10.upto(20) do |i|
@@ -1097,6 +1097,21 @@ class TestBigDecimal < Test::Unit::TestCase
     GC.stress = stress
   end
 
+  def test_coerce_under_gc_stress
+    expect = ":too_long_to_embed_as_string can't be coerced into BigDecimal"
+    under_gc_stress do
+      b = BigDecimal.new("1")
+      10.times do
+        begin
+          b.coerce(:too_long_to_embed_as_string)
+        rescue => e
+          assert_instance_of TypeError, e
+          assert_equal expect, e.message
+        end
+      end
+    end
+  end
+
   def test_INFINITY
     assert(BigDecimal::INFINITY.infinite?, "BigDecimal::INFINITY is not a infinity")
   end
@@ -1157,6 +1172,20 @@ class TestBigDecimal < Test::Unit::TestCase
     assert_in_epsilon(Math.exp(-40), BigMath.exp(BigDecimal("-40"), n))
   end
 
+  def test_BigMath_exp_under_gc_stress
+    expect = ":too_long_to_embed_as_string can't be coerced into BigDecimal"
+    under_gc_stress do
+      10.times do
+        begin
+          BigMath.exp(:too_long_to_embed_as_string, 6)
+        rescue => e
+          assert_instance_of ArgumentError, e
+          assert_equal expect, e.message
+        end
+      end
+    end
+  end
+
   def test_BigMath_log_with_nil
     assert_raise(ArgumentError) do
       BigMath.log(nil, 20)
@@ -1241,4 +1270,18 @@ class TestBigDecimal < Test::Unit::TestCase
     assert_in_delta(Math.log(1e-42), BigMath.log(1e-42, 20))
     assert_in_delta(Math.log(1e-42), BigMath.log(BigDecimal("1e-42"), 20))
   end
+
+  def test_BigMath_log_under_gc_stress
+    expect = ":too_long_to_embed_as_string can't be coerced into BigDecimal"
+    under_gc_stress do
+      10.times do
+        begin
+          BigMath.log(:too_long_to_embed_as_string, 6)
+        rescue => e
+          assert_instance_of ArgumentError, e
+          assert_equal expect, e.message
+        end
+      end
+    end
+  end
 end

test/bigdecimal/testbase.rb

@@ -17,4 +17,11 @@ module TestBigDecimalBase
       BigDecimal.mode(mode, !(@mode & mode).zero?)
     end
   end
+
+  def under_gc_stress
+    stress, GC.stress = GC.stress, true
+    yield
+  ensure
+    GC.stress = stress
+  end
 end