web: static: Build website from within temporary clone of repo.

The build process may run code that expects files to be on the
filesystem. Not all of this file accessing code is within tissue's
control. Think arbitrary code in skribilo documents. So, we cannot
always work around this by pointing file accesses into a bare git
repository.

* tissue/web/static.scm: Import (git).
(build-website): Move into temporary clone of git repository before
building files.
(exporter): Use call-with-input-file instead of call-with-file-in-git.

1 files changed, 19 insertions, 14 deletions

diff --git a/tissue/web/static.scm b/tissue/web/static.scm
index fbef99e..795ccee 100644
--- a/tissue/web/static.scm
+++ b/tissue/web/static.scm
@@ -30,6 +30,7 @@
   #:use-module (skribilo evaluator)
   #:use-module (skribilo reader)
   #:use-module (web uri)
+  #:use-module (git)
   #:use-module (tissue git)
   #:use-module (tissue issue)
   #:use-module (tissue utils)
@@ -62,7 +63,7 @@ NEW-EXTENSION."
 @var{proc}. @var{proc} is passed two arguments---the input port to
 read from and the output port to write to."
   (lambda (out)
-    (call-with-file-in-git (current-git-repository) file
+    (call-with-input-file file
       (cut proc <> out))))
 
 (define (copier file)
@@ -132,16 +133,20 @@ the web output.
 Log to LOG-PORT. When LOG-PORT is #f, do not log."
   ;; Create output directory.
   (make-directories output-directory)
-  ;; Write each of the <file> objects.
-  (for-each (lambda (file)
-              (let ((output-file
-                     (string-append output-directory "/" (file-name file))))
-                (when log-port
-                  (display (file-name file) log-port)
-                  (newline log-port))
-                (make-directories (dirname output-file))
-                (call-with-output-file output-file
-                  (lambda (port)
-                    (call-with-current-directory repository-top-level
-                      (cut (file-writer file) port))))))
-            files))
+  ;; Move into a temporary clone of the git repository, and write each
+  ;; of the <file> objects.
+  (call-with-temporary-directory
+   (lambda (temporary-repository-clone)
+     (clone repository-top-level temporary-repository-clone)
+     (for-each (lambda (file)
+                 (let ((output-file
+                        (string-append output-directory "/" (file-name file))))
+                   (when log-port
+                     (display (file-name file) log-port)
+                     (newline log-port))
+                   (make-directories (dirname output-file))
+                   (call-with-output-file output-file
+                     (lambda (port)
+                       (call-with-current-directory temporary-repository-clone
+                         (cut (file-writer file) port))))))
+               files))))