Update way to deliver parameterized exceptions so the client doesn't need special handling

doc/sql.extensions/README.exception_handling

@@ -103,13 +103,11 @@ Parameterized exceptions (FB 3.0)
   Notes:
     The status vector is generated using that codes combination:
       isc_except, <exception number>,
-      isc_formatted_exception, <exception message>, <exception parameters>
+      isc_formatted_exception, <formatted exception message>,
+          <defined exception message>, <exception parameters>
 
-    The client library formats isc_formatted_exception in an special way, using the exception
-    parameters as argument to the exception message, instead of formatting all arguments of
-    isc_formatted_exception for a predefined internal text. That's important for any code that
-    formats status vectors without the help of the client library. Also, the client library older
-    than 3.0 will not be able to correctly format exceptions raised in this new way.
+    Since new error code (isc_formatted_exception) is used, it's necessary that the client is v3.0
+    or at least uses firebird.msg from v3.0 so that it can translate the status vector to string.
 
     @N means the N parameter (where N starts at 1) passed in the exception raise command. If a N
     parameter is not passed, the text is not substituted. If NULL is passed, it's replaced by string

src/common/classes/BaseStream.h

@@ -31,6 +31,7 @@
 #include <io.h>
 #endif
 
+#include "../common/classes/fb_string.h"
 #include <stdio.h>
 
 namespace MsgFormat
@@ -110,6 +111,26 @@ private:
 	char* m_current_pos;
 };
 
+
+// Wraps a reference to a Firebird::string.
+class StringRefStream : public BaseStream
+{
+public:
+	StringRefStream(Firebird::string& aRef)
+		: ref(aRef)
+	{
+	}
+
+	virtual int write(const void* str, unsigned int n)
+	{
+		ref.append((const char*) str, n);
+		return n;
+	}
+
+private:
+	Firebird::string& ref;
+};
+
 } // namespace
 
 #endif // FB_BASESTREAM_H

src/common/classes/MsgPrint.cpp

@@ -259,9 +259,8 @@ int MsgPrint(BaseStream& out_stream, const char* format, const SafeArg& arg, boo
 				break;
 			default:
 				{
-					const int start = userFormatting ? 1 : 0;
-					const int pos = start + iter[1] - '0';
-					if (pos > start && static_cast<size_t>(pos) <= arg.m_count)
+					const int pos = iter[1] - '0';
+					if (pos > 0 && static_cast<size_t>(pos) <= arg.m_count)
 						out_bytes += MsgPrintHelper(out_stream, arg.m_arguments[pos - 1]);
 					else
 					{
@@ -378,18 +377,7 @@ int fb_msg_format(void* handle, USHORT facility, USHORT number, unsigned int bsi
 			total_msg = fb_utils::snprintf(buffer, bsize, msg, rep[0], rep[1], rep[2], rep[3], rep[4]);
 		}
 		else
-		{
-			if (ENCODE_ISC_MSG(number, facility) == isc_formatted_exception && arg.getCount() > 0)
-			{
-				Firebird::HalfStaticArray<char, BUFFER_SMALL> msgBuffer(bsize);
-				MsgFormat::StringStream msgStream(msgBuffer.begin(), bsize);
-				MsgPrintHelper(msgStream, arg.getCell(0));
-
-				total_msg = MsgPrint(buffer, bsize, msgBuffer.begin(), arg, 1);
-			}
-			else
-				total_msg = MsgPrint(buffer, bsize, msg, arg);
-		}
+			total_msg = MsgPrint(buffer, bsize, msg, arg);
 	}
 	else
 	{

src/common/classes/MsgPrint.h

@@ -95,6 +95,7 @@ int MsgPrint(char* plainstring, unsigned int s_size, const char* format, const S
 
 // E. Prints a formatted string into stderr and flushed the buffer.
 int MsgPrintErr(const char* format, const SafeArg& arg, bool userFormatting = false);
+
 } // namespace
 
 // Type safe replacement of the old gds__msg_format.

src/dsql/StmtNodes.cpp

@@ -20,6 +20,8 @@
 
 #include "firebird.h"
 #include "../jrd/common.h"
+#include "../common/classes/BaseStream.h"
+#include "../common/classes/MsgPrint.h"
 #include "../dsql/StmtNodes.h"
 #include "../dsql/node.h"
 #include "../jrd/jrd.h"
@@ -934,13 +936,11 @@ void ExceptionNode::setError(thread_db* tdbb) const
 			{
 				status << Arg::Gds(isc_except) << Arg::Num(xcpCode) <<
 						  Arg::Gds(isc_random) << Arg::Str(exName) <<
-						  Arg::Gds(msgCode) << Arg::Str(s);
+						  Arg::Gds(msgCode);
 			}
 			else if (s)
-			{
 				status << Arg::Gds(isc_except) << Arg::Num(xcpCode) <<
-						  Arg::Gds(msgCode) << Arg::Str(s);
-			}
+						  Arg::Gds(msgCode);
 			else if (exName.hasData())
 			{
 				ERR_post(Arg::Gds(isc_except) << Arg::Num(xcpCode) <<
@@ -949,7 +949,8 @@ void ExceptionNode::setError(thread_db* tdbb) const
 			else
 				ERR_post(Arg::Gds(isc_except) << Arg::Num(xcpCode));
 
-			// Preallocate the strings, because Arg::StatusVector store the pointers.
+			// Preallocate objects, because Arg::StatusVector store pointers.
+			string formattedMsg;
 			ObjectsArray<string> paramsStr;
 
 			if (parameters)
@@ -964,11 +965,24 @@ void ExceptionNode::setError(thread_db* tdbb) const
 						paramsStr.push(MOV_make_string2(tdbb, value, ttype_metadata));
 				}
 
-				// And add the values to the status vector only when they are all created and will
-				// not move in paramsStr.
+				// And add the values to the args and status vector only after they are all created
+				// and will not move in paramsStr.
+
+				MsgFormat::SafeArg arg;
+				for (unsigned i = 0; i < parameters->nod_count; ++i)
+					arg << paramsStr[i].c_str();
+
+				MsgFormat::StringRefStream stream(formattedMsg);
+				MsgFormat::MsgPrint(stream, s, arg, true);
+
+				status << formattedMsg;
+				status << s;	// add the exception text
+
 				for (unsigned i = 0; i < parameters->nod_count; ++i)
 					status << paramsStr[i];
 			}
+			else
+				status << s;	// add the exception text
 
 			ERR_post(status);
 		}