| Type | Bug | Status | tested | Date | 31-Jul-2009 18:52 |
|---|---|---|---|---|---|
| Version | alpha 76 | Category | Native | Submitted by | BrianH |
| Platform | All | Severity | tweak | Priority | normal |
| Summary | MAKE object broken with aliased proto fields |
|---|---|
| Description |
I'm not sure how important this bug is, but the behavior of MAKE proto-object is off when the proto has aliased fields. The resulting object has the last of the aliased fields assigned rather than the first, which means that any references return the original first slot value, not the changed value. It doesn't matter whichever order the words were specified in the call to ALIAS - the first aliased slot of an object is always referenced, and the last aliased slot of the proto is always propagated. If the latter aliased slots are copied to the new object at all, the first slot is the one that should be modified by any spec code, not the last. |
| Example code |
>> o: context [a: 1 b: 2 c: 3]
== make object! [
a: 1
b: 2
c: 3
]
>> alias 'a "b"
== b
>> alias 'a "c"
== c
>> o2: make o [a: 99]
== make object! [
a: 1 ; should be 99
b: 2 ; should be 99, or 2, or not here at all
c: 99 ; should be 99, or 3, or not here at all
]
>> o2/a
== 1
>> o2/b
== 1
>> o2/c
== 1
|
| Assigned to | n/a | Fixed in | alpha 111 | Last Update | 26-Feb-2011 01:12 |
|---|
| Comments | |
|---|---|
|
(0001457)
Carl 3-Aug-2009 19:34 |
This is an interesting bug. I'm going to mark it reviewed for closer study.
Essentially, if this bug is true, then the same type of error can be achieved via capitalization differences, since they are also aliases. That would be quite serious. Bumped severity to major. |
|
(0001462)
BrianH 4-Aug-2009 19:54 |
This bug only affects words that are aliased after they are loaded into an object. Words that differ only in capitalization are aliased at word creation time, before they are used. So attempts to add them to an object will operate on the original slot.
In regular code this will usually affect usage of ALIAS word! word! (see #341, #1163, #1164). |
|
(0001559)
BrianH 21-Aug-2009 20:29 |
As of alpha 79 and the fixing of #341, this will only affect ALIAS in code that would break in R2: Words that differ in spelling, not in capitalization, and have already been used somewhere. |
|
(0003071)
BrianH 31-Jan-2011 06:19 |
The ALIAS function has been removed in alpha 111. See #1835 for details. |
| Date | User | Field | Action | Change |
|---|---|---|---|---|
| 26-Feb-2011 01:12 | BrianH | Status | Modified | built => tested |
| 31-Jan-2011 06:19 | BrianH | Comment : 0003071 | Added | - |
| 31-Jan-2011 06:18 | BrianH | Fixedin | Modified | => alpha 111 |
| 31-Jan-2011 06:18 | BrianH | Status | Modified | reviewed => built |
| 22-Sep-2010 05:54 | carl | Severity | Modified | major => tweak |
| 21-Aug-2009 20:29 | BrianH | Comment : 0001559 | Added | - |
| 4-Aug-2009 19:56 | BrianH | Comment : 0001462 | Modified | - |
| 4-Aug-2009 19:54 | BrianH | Comment : 0001462 | Added | - |
| 3-Aug-2009 19:36 | carl | Comment : 0001457 | Modified | - |
| 3-Aug-2009 19:35 | carl | Comment : 0001457 | Modified | - |
| 3-Aug-2009 19:35 | carl | Description | Modified | - |
| 3-Aug-2009 19:35 | carl | Code | Modified | - |
| 3-Aug-2009 19:35 | carl | Severity | Modified | minor => major |
| 3-Aug-2009 19:35 | carl | Status | Modified | submitted => reviewed |
| 3-Aug-2009 19:34 | carl | Comment : 0001457 | Added | - |
| 31-Jul-2009 18:52 | BrianH | Ticket | Added | - |