[CONTRIB-90] clojure.contrib.io does not support appending anymore Created: 04/Aug/10 Updated: 26/Aug/10 |
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| Status: | In Progress |
| Project: | Clojure-Contrib |
| Component/s: | None |
| Affects Version/s: | None |
| Fix Version/s: | None |
| Type: | Defect | ||
| Reporter: | Anonymous | Assignee: | bpsm |
| Resolution: | Unresolved | Votes: | 0 |
| Labels: | None | ||
| Approval: | Test |
| Description |
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Reproduce the bug with: (require 'clojure.contrib.io) (clojure.contrib.io/append-writer "/xyz.txt") </code></pre> which will throw an Exception ���Cannot change an open stream to append mode���. This is caused because of a flaw in the call chain. *clojure.contrib.io/writer* for Strings calls again *writer* for whatever *clojure.contrib.io/output-stream* returns. We call *append-writer* which then calls *writer* on the String which in turn then calls: <pre><code> output-stream for ^String which calls output-stream for ^URL which calls output-stream for ^File which binds *append* to false and calls output-stream for ^OutputStream which returns a BufferedOutputStream instance which then jumps back to the ^File handler, which removes its binding for *append*!! and returns the BOS to the ^URL handler which returns the BOS to the ^String handler At this point the outer binding (for append) is set to true again, and assert-not-appending fails. |
| Comments |
| Comment by Assembla Importer [ 26/Aug/10 8:25 PM ] |
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Converted from http://www.assembla.com/spaces/clojure/tickets/90 |
| Comment by Assembla Importer [ 26/Aug/10 8:25 PM ] |
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bpsm said: I've looked at this defect (on master). It seems thorny to me. I'm finding the control flow in c.c.io rather difficult to follow, what with all those extensions of the Streams protocol delegating to one-another. I'm reasonably certain that the solution is to special case the creation of a reader in append mode. I'll attach a patch that does this by providing a default implementation for :writer, which seems to solve the problem, but I think I still need to think about it some more before I can call it 'done'. Note: this defect is also present in clojure.java.io 1.2.0. |
| Comment by Assembla Importer [ 26/Aug/10 8:25 PM ] |
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bpsm said: [file:auuXEWSiur35DyeJe5cbCb] |
| Comment by Assembla Importer [ 26/Aug/10 8:25 PM ] |
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bpsm said: Correction: This issue is not present in clojure 1.2.0. my bad. clojure.contrib.io> (require 'clojure.java.io)
nil
clojure.contrib.io> (in-ns 'clojure.java.io)
#<Namespace clojure.java.io>
clojure.java.io> (with-open [x (append-writer "/tmp/foo.txt")] x)
; Evaluation aborted. ;;; EXCEPTION HERE
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| Comment by Assembla Importer [ 26/Aug/10 8:25 PM ] |
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bpsm said: [file:amTyVwSt8r378NeJe5cbLr]: regression test |
| Comment by Assembla Importer [ 26/Aug/10 8:25 PM ] |
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bpsm said: The provided regression test demonstrates the described issue and confirms that the provided patch resolves the issue. All other io unit tests continue to pass. |
| Comment by Assembla Importer [ 26/Aug/10 8:25 PM ] |
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stuart.sierra said: clojure.contrib.io is deprecated and will be removed before the next release. |
| Comment by Assembla Importer [ 26/Aug/10 8:25 PM ] |
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bpsm said: Let's see if I'm on the same page that you're on: Since 1.2.0 is at RC3 already, you must mean 1.3.0 when you say "next release", yes/no? Predicated on that:
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