Use precondition instead of raising an exception.

Fixed bug#14062: CURL dynamic library not found exception is causing an internal failure in WEL

git-svn-id: https://svn.origo.ethz.ch/eiffelstudio/trunk/Src/library/cURL@72612 8089f293-4706-0410-a29e-feb5c42a2edf

curl_dynamic_library_not_found_exception.e

@@ -1,40 +0,0 @@
-indexing
-	description: "[
-					Exception which means cURL dynamic library (*.dll on Windows,
-					*.so on Linux and ...) not found.
-																			]"
-	status: "See notice at end of class."
-	legal: "See notice at end of class."
-	date: "$Date$"
-	revision: "$Revision$"
-
-class
-	CURL_DYNAMIC_LIBRARY_NOT_FOUND_EXCEPTION
-
-inherit
-	DEVELOPER_EXCEPTION
-
-create
-	make
-
-feature {NONE} -- Initialization
-
-	make is
-			-- Creation method.
-		do
-			set_message ("cURL dynamic library not found.")
-		end
-
-indexing
-	library:   "cURL: Library of reusable components for Eiffel."
-	copyright: "Copyright (c) 1984-2006, Eiffel Software and others"
-	license:   "Eiffel Forum License v2 (see http://www.eiffel.com/licensing/forum.txt)"
-	source: "[
-			Eiffel Software
-			356 Storke Road, Goleta, CA 93117 USA
-			Telephone 805-685-1006, Fax 805-685-6869
-			Website http://www.eiffel.com
-			Customer support http://support.eiffel.com
-		]"
-
-end

curl_easy_externals.e

@@ -16,16 +16,14 @@ feature -- Command
 
 	init: POINTER is
 			-- Declared as curl_easy_init().
+		require
+			dynamic_library_exists: is_dynamic_library_exists
 		local
 			l_api: POINTER
-			l_exception: CURL_DYNAMIC_LIBRARY_NOT_FOUND_EXCEPTION
 		do
 			l_api := api_loader.safe_load_api (module_name, "curl_easy_init")
 			if l_api /= default_pointer then
 				Result := c_init (l_api)
-			else
-				create l_exception.make
-				l_exception.raise
 			end
 		ensure
 			exists: Result /= default_pointer
@@ -126,6 +124,14 @@ feature -- Command
 			end
 		end
 
+feature -- Query
+
+	is_dynamic_library_exists: BOOLEAN is
+			-- If dll/so files exist?
+		do
+			Result := (api_loader.module_pointer (module_name) /= default_pointer)
+		end
+		
 feature -- Special setting
 
 	set_curl_function (a_curl_function: CURL_FUNCTION) is

curl_externals.e

@@ -16,16 +16,14 @@ feature -- Command
 
 	global_init is
 			-- Declared as curl_global_init().
+		require
+			dynamic_library_exists: is_dynamic_library_exists
 		local
 			l_ptr: POINTER
-			l_exception: CURL_DYNAMIC_LIBRARY_NOT_FOUND_EXCEPTION
 		do
 			l_ptr := api_loader.safe_load_api (module_name, "curl_global_init")
 			if l_ptr /= default_pointer then
 				c_curl_global_init (l_ptr, {CURL_GLOBAL_CONSTANTS}.curl_global_all);
-			else
-				create l_exception.make
-				l_exception.raise
 			end
 		end