Fix to issue #1212.

deploy.php

@@ -61,9 +61,7 @@ if (!is_null($deploy)) {
 $undeploy = optional_param('undeploy', null, PARAM_INT);
 if (!is_null($undeploy)) {
     $question->undeploy_variant($undeploy);
-
-    // As we redirect, switch to the undeployed variant, so it easy to re-deploy
-    // if you just made a mistake.
+    // As we redirect, switch to the undeployed variant, so it easy to re-deploy if you just made a mistake.
     $nexturl->param('seed', $undeploy);
     redirect($nexturl);
 }
@@ -83,7 +81,9 @@ $deployfromlist = optional_param('deployfromlist', null, PARAM_INT);
 $deploysystematic = optional_param('deploysystematic', null, PARAM_INT);
 $deploysystematicfrom = optional_param('deploysystematicfrom', null, PARAM_INT);
 $deploysystematicto = optional_param('deploysystematicto', null, PARAM_INT);
-if (!is_null($deployfromlist) || !is_null($deploysystematic) || (!is_null($deploysystematicfrom) && !is_null($deploysystematicto))) {
+$usefromtofeature = false;
+if (!is_null($deployfromlist) || !is_null($deploysystematic) || (!is_null($deploysystematicfrom) &&
+    !is_null($deploysystematicto))) {
 
     // Check data integrity.
     $dataproblem = false;
@@ -137,7 +137,7 @@ if (!is_null($deployfromlist) || !is_null($deploysystematic) || (!is_null($deplo
     }
 
     // Undeploy all existing variants.
-    // If the deploy-from-to feature is used, only undeploy variants that already exist
+    // If the deploy-from-to feature is used, only undeploy variants that already exist.
     if ($question->deployedseeds) {
         if ($usefromtofeature) {
             foreach ($question->deployedseeds as $seed) {

doc/en/Developer/Development_track.md

@@ -13,6 +13,7 @@ DONE
 2. Add in stack preamble via `%_stack_preamble_end;` in the question variables to allow some variables to be available in inputs.  This fixes [issue #1207](https://github.com/maths/moodle-qtype_stack/issues/1207]) and [issue #1133](https://github.com/maths/moodle-qtype_stack/issues/1133).
 3. Allow Maxima code in keyvals to terminate expressions with a `$` (as in Maxima) [issue #1019](https://github.com/maths/moodle-qtype_stack/issues/1019]).  This will allow better copy/paste to and from desktop maxima.
 4. Add in an option to fine-tune the multiplication sign used for scientific units:  `multsgnstackunits`.  See discussion in [issue #1080](https://github.com/maths/moodle-qtype_stack/issues/1080]).
+5. Add in the "Deploy from n to m" deature to systematically deploy seeds.
 
 Issues with [github milestone 4.7.0](https://github.com/maths/moodle-qtype_stack/issues?q=is%3Aissue+milestone%3A4.7.0) include