[API] Fixed the "greedy" regex in the Utils.__rescue_from_not_found…

… method

The previous implementation of the `Utils.__rescue_from_not_found` method matched the exception
method on a pattern including `404`, which has led to incorrectly capturing eg. the
`Elasticsearch::Transport::Transport::Errors::Conflict` exception, when the document
version or ID contained the `404` string.

This patch narrows the regex pattern to only look for the "Not Found" string, in order
with the original motivation to enable this functionality also in custom clients,
not based on the `elasticsearch-transport` Rubygem.

It also fixes the `rescue` clause itself, to only catch exceptions descending from
`StandardError`, not `Exception`.

Tests have been updated accordingly.

Closes #490

elasticsearch-api/lib/elasticsearch/api/utils.rb

@@ -187,17 +187,21 @@ def __extract_parts(arguments, valid_parts=[])
         return parts
       end
 
-      # Calls given block, rescuing from any exceptions. Returns `false`
-      # if exception contains NotFound/404 in its class name or message, else re-raises exception.
+      # Calls the given block, rescuing from `StandardError`.
+      #
+      # Primary use case is the `:ignore` parameter for API calls.
+      #
+      # Returns `false` if exception contains NotFound in its class name or message,
+      # else re-raises the exception.
       #
       # @yield [block] A block of code to be executed with exception handling.
       #
       # @api private
       #
       def __rescue_from_not_found(&block)
         yield
-      rescue Exception => e
-        if e.class.to_s =~ /NotFound/ || e.message =~ /Not\s*Found|404/i
+      rescue StandardError => e
+        if e.class.to_s =~ /NotFound/ || e.message =~ /Not\s*Found/i
           false
         else
           raise e

elasticsearch-api/test/unit/utils_test.rb

@@ -237,16 +237,13 @@ class UtilsTest < UnitTest
           end
 
           should "return false if exception message contains 'Not Found'" do
-            assert_equal( false, __rescue_from_not_found { raise Exception.new "Not Found" })
-          end
-
-          should "return false if exception message contains '404'" do
-            assert_equal( false, __rescue_from_not_found { raise Exception.new "404" })
+            assert_equal( false, __rescue_from_not_found { raise StandardError.new "Not Found" })
+            assert_equal( false, __rescue_from_not_found { raise StandardError.new "NotFound" })
           end
 
           should "raise exception if exception class name and message do not contain NotFound/404" do
-            assert_raise Exception do
-              __rescue_from_not_found { raise Exception.new "Any other exception" }
+            assert_raise StandardError do
+              __rescue_from_not_found { raise StandardError.new "Any other exception" }
             end
           end