Avoid null characters in package descriptions

guix-data-service/model/package-metadata.scm

@@ -322,7 +322,12 @@ WHERE packages.id IN (
                        (list->vector
                         (map (match-lambda
                                ((locale . description)
-                                (list locale description)))
+                                (list locale
+                                      ;; \u0000 has appeared in package
+                                      ;; descriptions (#71968), so strip it
+                                      ;; out here to avoid PostgreSQL throwing
+                                      ;; an error
+                                      (string-delete-null description))))
                              package-description-data)))))
                    package-metadata-list))))
      (with-time-logging "preparing package synopsis set ids"

guix-data-service/model/utils.scm

@@ -24,7 +24,8 @@
   #:use-module (squee)
   #:use-module (guix-data-service database)
   #:use-module (guix-data-service utils)
-  #:export (quote-string
+  #:export (string-delete-null
+            quote-string
             value->quoted-string-or-null
             non-empty-string-or-false
             parse-postgresql-array-string
@@ -39,6 +40,12 @@
             insert-and-return-id
             prepare-insert-and-return-id))
 
+(define (char-null? c)
+  (char=? c #\null))
+
+(define (string-delete-null s)
+  (string-delete char-null? s))
+
 (define (quote-string s)
   (string-append "$STR$" s "$STR$"))