script: fix crash on "/script update" if a script detail is displayed in buffer (closes #177)

(cherry picked from commit 067f310be6)

ChangeLog.asciidoc

@@ -22,6 +22,8 @@ http://weechat.org/files/releasenotes/ReleaseNotes-devel.html[release notes]
 * tests: fix memory leak in tests launcher
 * aspell: fix crash with command "/aspell addword" if no word is given
   (closes #164, closes #165)
+* script: fix crash on "/script update" if a script detail is displayed in
+  buffer (closes #177)
 * trigger: fix regex used in default triggers to hide passwords ("\S" is not
   supported on *BSD) (closes #172)
 

src/plugins/script/script-repo.c

@@ -652,6 +652,10 @@ script_repo_remove (struct t_script_repo *script)
 {
     struct t_script_repo *new_scripts_repo;
 
+    /* unlink script from buffer (if it is used) */
+    if (script_buffer_detail_script == script)
+        script_buffer_detail_script = NULL;
+
     /* remove script from list */
     if (last_script_repo == script)
         last_script_repo = script->prev_script;