ui: Gracefully handle Unicode description strings.

Fixes <http://bugs.gnu.org/21536>.
Reported by Alex Kost <alezost@gmail.com>.

* guix/ui.scm (texi->plain-text): Wrap body in 'with-fluids'.
* tests/ui.scm ("package-description-string vs. Unicode"): New test.

1 files changed, 7 insertions, 0 deletions

diff --git a/tests/ui.scm b/tests/ui.scm
index 25fc7094317..bd4c907525c 100644
--- a/tests/ui.scm
+++ b/tests/ui.scm
@@ -22,6 +22,7 @@
   #:use-module (guix profiles)
   #:use-module (guix store)
   #:use-module (guix derivations)
+  #:use-module (guix tests)
   #:use-module (srfi srfi-1)
   #:use-module (srfi srfi-11)
   #:use-module (srfi srfi-19)
@@ -89,6 +90,12 @@ interface, and powerful string processing.")
   (fill-paragraph "First line.
 Second line" 24))
 
+(test-equal "package-description-string vs. Unicode"
+  "b•ll•t\n\n"                                ;see <http://bugs.gnu.org/21536>
+  (with-fluids ((%default-port-encoding "ISO-8859-1"))
+    (package-description-string
+     (dummy-package "foo" (description "b•ll•t")))))
+
 (test-equal "package-specification->name+version+output"
   '(("guile" #f "out")
     ("guile" "2.0.9" "out")