Subject: [PATCH] scripts: hash: Handle repository with different VCS folders.

From: Simon Tournier <[email-masked]>
Date: Mon, 6 Nov 2023 00:00:55 +0100

Fixes <https://issues.guix.gnu.org/issue/65979>.
Reported by Simon Tournier <[email-masked]>

* guix/hash.scm (vcs-file?): Add optional argument for passing VCS kind of the
file/repository.
(file-hash*): Adjust accordingly.
* guix/scripts/hash.scm (guix-hash)[file-hash]: Detect VCS kind of the
file/repository and passes it.

Change-Id: I8e286c3426ddefd664dc3a471d5a09e309824faa
---
 guix/hash.scm         | 18 ++++++++++++------
 guix/scripts/hash.scm | 18 +++++++++++++-----
 2 files changed, 25 insertions(+), 11 deletions(-)

Hi,

I re-resend this patch for more attractions in case I have missed
something. :-)  It had already been send more than 2 weeks ago as an answer to
#65979.

It fixes a corner case of "guix hash".

--8<---------------cut here---------------start------------->8---
$ git clone https://github.com/s-andrews/FastQC /tmp/FastQC
$ git -C /tmp/FastQC/ checkout v0.11.9

$ find /tmp/FastQC/ -type d -name ".git" -print
/tmp/FastQC/.git
$ find /tmp/FastQC/ -type d -name ".svn" -print
/tmp/FastQC/Help/1 Introduction/.svn
/tmp/FastQC/Help/3 Analysis Modules/.svn
/tmp/FastQC/Help/2 Basic Operations/.svn

$ guix hash -rx /tmp/FastQC
0jyk90kg6s62w3dn6qjx9nrawjs12qx172lii0yxbvsfylhnx479

$ grep -A 15 'define-public fastqc' gnu/packages/bioinformatics.scm | grep -C 1 base32
       (sha256
        (base32
         "00y9drm0bkpxw8xfl8ysss18jmnhj8blgqgr6fpa58rkpfcbg8qk"))

$ ./pre-inst-env guix hash -rx /tmp/FastQC
00y9drm0bkpxw8xfl8ysss18jmnhj8blgqgr6fpa58rkpfcbg8qk
--8<---------------cut here---------------end--------------->8---

And it does not introduce any significant penalty:

--8<---------------cut here---------------start------------->8---
$ time guix hash -rx .
093w70scf2v64bdbln5m2xjm63pzfib903w1mcb2smj32g0w8y63

real	0m9.730s
user	0m20.468s
sys	0m1.487s

$ time ./pre-inst-env guix hash -rx .
093w70scf2v64bdbln5m2xjm63pzfib903w1mcb2smj32g0w8y63

real	0m9.632s
user	0m20.320s
sys	0m1.541s
--8<---------------cut here---------------end--------------->8---

WDYT?

Cheers,
simon

diff --git a/guix/hash.scm b/guix/hash.scm
index 3cb68e5c44..8fff51e8f1 100644
--- a/guix/hash.scm
+++ b/guix/hash.scm
@@ -1,6 +1,7 @@
 ;;; GNU Guix --- Functional package management for GNU
 ;;; Copyright © 2021 Sarah Morgensen <[email-masked]>
 ;;; Copyright © 2022 Maxime Devos <[email-masked]>
+;;; Copyright © 2023 Simon Tournier <[email-masked]>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -25,21 +26,26 @@ (define-module (guix hash)
   #:export (vcs-file?
             file-hash*))
 
-(define (vcs-file? file stat)
-  "Returns true if FILE is a version control system file."
+(define* (vcs-file? file stat
+                    #:optional
+                    (vcses (list ".bzr" ".git" ".hg" ".svn" "CVS")))
+  "Returns true if FILE matches a version control system from the list VCSES."
   (case (stat:type stat)
     ((directory)
-     (member (basename file) '(".bzr" ".git" ".hg" ".svn" "CVS")))
+     (member (basename file) vcses))
     ((regular)
-     ;; Git sub-modules have a '.git' file that is a regular text file.
-     (string=? (basename file) ".git"))
+     (if (member ".git" vcses)
+         ;; Git sub-modules have a '.git' file that is a regular text file.
+         (string=? (basename file) ".git")
+         #f))
     (else
      #f)))
 
 (define* (file-hash* file #:key
                      (algorithm (hash-algorithm sha256))
                      (recursive? 'auto)
-                     (select? (negate vcs-file?)))
+                     (select? (negate (lambda (file stat)
+                                        (vcs-file? file stat)))))
   "Compute the hash of FILE with ALGORITHM.
 
 Symbolic links are only dereferenced if RECURSIVE? is false.
diff --git a/guix/scripts/hash.scm b/guix/scripts/hash.scm
index 7197d3965c..ed96e6a7e1 100644
--- a/guix/scripts/hash.scm
+++ b/guix/scripts/hash.scm
@@ -3,7 +3,7 @@
 ;;; Copyright © 2013 Nikita Karetnikov <[email-masked]>
 ;;; Copyright © 2016 Jan Nieuwenhuizen <[email-masked]>
 ;;; Copyright © 2018 Tim Gesthuizen <[email-masked]>
-;;; Copyright © 2021 Simon Tournier <[email-masked]>
+;;; Copyright © 2021, 2023 Simon Tournier <[email-masked]>
 ;;; Copyright © 2021 Sarah Morgensen <[email-masked]>
 ;;;
 ;;; This file is part of GNU Guix.
@@ -181,9 +181,6 @@ (define-command (guix-hash . args)
                             (_ #f))
                            (reverse opts)))
          (fmt  (assq-ref opts 'format))
-         (select? (if (assq-ref opts 'exclude-vcs?)
-                      (negate vcs-file?)
-                      (const #t)))
          (algorithm (assoc-ref opts 'hash-algorithm))
          (serializer (assoc-ref opts 'serializer)))
 
@@ -193,7 +190,18 @@ (define-command (guix-hash . args)
       (catch 'system-error
         (lambda _
           (with-error-handling
-            (serializer file algorithm select?)))
+            (let* ((vcses (fold (lambda (vcs result)
+                                  (if (file-exists? (string-append file "/" vcs))
+                                      (cons vcs result)
+                                      result))
+                                '()
+                                (list ".bzr" ".git" ".hg" ".svn" "CVS")))
+                   (select? (if (assq-ref opts 'exclude-vcs?)
+                                (negate (lambda (file stat)
+                                          (vcs-file? file stat
+                                                     vcses)))
+                                (const #t))))
+              (serializer file algorithm select?))))
         (lambda args
           (leave (G_ "~a ~a~%")
                  file

base-commit: 08d94fe20eca47b69678b3eced8749dd02c700a4
-- 
2.41.0