Improve exceptions.

FossilOrigin-Name: 12b5ef483a1f9eae92df83cf8a6aded299ef10dd2972059a36c79d299e676a0d

exceptions/PGCommandFailedException.h

@@ -9,11 +9,9 @@
 @property (readonly, copy, nonatomic) OFString *command;
 #endif
 
-+ exceptionWithClass: (Class)class_
-	  connection: (PGConnection*)connection
++ (instancetype)exceptionWithConnection: (PGConnection*)connection
+				command: (OFString*)command;
+- initWithConnection: (PGConnection*)connection
 	     command: (OFString*)command;
-- initWithClass: (Class)class_
-     connection: (PGConnection*)connection
-	command: (OFString*)command;
 - (OFString*)command;
 @end

exceptions/PGCommandFailedException.m

@@ -1,21 +1,17 @@
 #import "PGCommandFailedException.h"
 
 @implementation PGCommandFailedException
-+ exceptionWithClass: (Class)class
-	  connection: (PGConnection*)connection
-	     command: (OFString*)command
++ (instancetype)exceptionWithConnection: (PGConnection*)connection
+				command: (OFString*)command
 {
-	return [[[self alloc] initWithClass: class
-				 connection: connection
-				    command: command] autorelease];
+	return [[[self alloc] initWithConnection: connection
+					 command: command] autorelease];
 }
 
-- initWithClass: (Class)class
-     connection: (PGConnection*)connection
-	command: (OFString*)command
+- initWithConnection: (PGConnection*)connection
+	     command: (OFString*)command
 {
-	self = [super initWithClass: class
-			 connection: connection];
+	self = [super initWithConnection: connection];
 
 	@try {
 		_command = [command copy];
@@ -36,10 +32,8 @@
 
 - (OFString*)description
 {
-	return [OFString stringWithFormat:
-	    @"A PostgreSQL command in class %@ failed: %s\nCommand: %@",
-	    [self inClass], PQerrorMessage([_connection PG_connection]),
-	    _command];
+	return [OFString stringWithFormat: @"A PostgreSQL command failed: %@\n"
+					   @"Command: %@", _error, _command];
 }
 
 - (OFString*)command

exceptions/PGConnectionFailedException.m

@@ -4,9 +4,7 @@
 - (OFString*)description
 {
 	return [OFString stringWithFormat:
-	    @"Establishing a PostgreSQL connection in class %@ failed:\n%s\n"
-	    "Parameters: %@", [self inClass],
-	    PQerrorMessage([_connection PG_connection]),
-	    [_connection parameters]];
+	    @"Establishing a PostgreSQL connection failed:\n%@\n"
+	    "Parameters: %@", _error, [_connection parameters]];
 }
 @end

exceptions/PGException.h

@@ -5,15 +5,14 @@
 @interface PGException: OFException
 {
 	PGConnection *_connection;
+	OFString *_error;
 }
 
 #ifdef OF_HAVE_PROPERTIES
 @property (readonly, retain, nonatomic) PGConnection *connection;
 #endif
 
-+ exceptionWithClass: (Class)class_
-	  connection: (PGConnection*)connection;
-- initWithClass: (Class)class_
-     connection: (PGConnection*)connection;
++ (instancetype)exceptionWithConnection: (PGConnection*)connection;
+- initWithConnection: (PGConnection*)connection;
 - (PGConnection*)connection;
 @end

exceptions/PGException.m

@@ -1,19 +1,24 @@
 #import "PGException.h"
 
 @implementation PGException
-+ exceptionWithClass: (Class)class
-	  connection: (PGConnection*)connection
++ (instancetype)exceptionWithConnection: (PGConnection*)connection
 {
-	return [[[self alloc] initWithClass: class
-				 connection: connection] autorelease];
+	return [[[self alloc] initWithConnection: connection] autorelease];
 }
 
-- initWithClass: (Class)class
-     connection: (PGConnection*)connection
+- initWithConnection: (PGConnection*)connection
 {
-	self = [super initWithClass: class];
+	self = [super init];
 
-	_connection = [connection retain];
+	@try {
+		_connection = [connection retain];
+		_error = [[OFString alloc]
+		    initWithCString: PQerrorMessage([_connection PG_connection])
+			   encoding: OF_STRING_ENCODING_NATIVE];
+	} @catch (id e) {
+		[self release];
+		@throw e;
+	}
 
 	return self;
 }
@@ -21,15 +26,15 @@
 - (void)dealloc
 {
 	[_connection release];
+	[_error release];
 
 	[super dealloc];
 }
 
 - (OFString*)description
 {
-	return [OFString stringWithFormat:
-	    @"A PostgreSQL operation in class %@ failed: %s", [self inClass],
-	    PQerrorMessage([_connection PG_connection])];
+	return [OFString stringWithFormat: @"A PostgreSQL operation failed: %@",
+					   _error];
 }
 
 - (PGConnection*)connection