Fix for the bugs:

#2005 Long decimal comparion bug.                                               
#2055 mysqldump should replace "-inf" numeric field values with "NULL"

client/mysqldump.c

@@ -1067,10 +1067,22 @@ static void dumpTable(uint numFields, char *table)
 	      }
 	      else
 	      {
-		/* change any strings ("inf","nan",..) into NULL */
+		/* change any strings ("inf", "-inf", "nan") into NULL */
 		char *ptr = row[i];
-		dynstr_append(&extended_row,
-			      (!isalpha(*ptr)) ? ptr : "NULL");
+		if (isalpha(*ptr) || (*ptr == '-' && *(ptr+1) == 'i'))
+		  dynstr_append(&extended_row, "NULL");
+		else
+		{
+		  if (field->type == FIELD_TYPE_DECIMAL)
+		  {
+		    /* add " signs around */
+		    dynstr_append(&extended_row, "\"");
+		    dynstr_append(&extended_row, ptr);
+		    dynstr_append(&extended_row, "\"");
+		  }
+		  else
+		    dynstr_append(&extended_row, ptr);
+		}
 	      }
 	    }
 	    else
@@ -1098,13 +1110,25 @@ static void dumpTable(uint numFields, char *table)
 	    }
 	    else
 	    {
-	      /* change any strings ("inf","nan",..) into NULL */
+	      /* change any strings ("inf", "-inf", "nan") into NULL */
 	      char *ptr = row[i];
 	      if (opt_xml)
 		fprintf(md_result_file, "\t\t<field name=\"%s\">%s</field>\n",
 			field->name,!isalpha(*ptr) ?ptr: "NULL");
+	      else if (isalpha(*ptr) || (*ptr == '-' && *(ptr+1) == 'i'))
+	        fputs("NULL", md_result_file);
+	      else
+	      {
+		if (field->type == FIELD_TYPE_DECIMAL)
+		{
+		  /* add " signs around */
+		  fputs("\"", md_result_file);
+		  fputs(ptr, md_result_file);
+		  fputs("\"", md_result_file);
+		}
 		else
-		fputs((!isalpha(*ptr)) ? ptr : "NULL", md_result_file);
+		  fputs(ptr, md_result_file);
+	      }
 	    }
 	  }
 	  else

mysql-test/t/mysqldump.test

@@ -8,3 +8,22 @@ CREATE TABLE t1(a int);
 INSERT INTO t1 VALUES (1), (2);
 --exec $MYSQL_DUMP -X test t1
 DROP TABLE t1;
+
+#
+# Bug #2005
+#
+
+CREATE TABLE t1 (a decimal(240, 20));
+INSERT INTO t1 VALUES ("1234567890123456789012345678901234567890"),
+("0987654321098765432109876543210987654321");
+--exec $MYSQL_DUMP test t1
+DROP TABLE t1;
+
+#
+# Bug #2055
+#
+
+CREATE TABLE t1 (a double);
+INSERT INTO t1 VALUES (-9e999999);
+--exec $MYSQL_DUMP test t1
+DROP TABLE t1;