Fix undefined $TextinFile/$keyval in bn_after_upload_gom.php

$TextinFile was passed to move_uploaded_file() as its $to argument, but
its assignment (and the $keyval/$sid/$dir it depends on) was commented
out, so $TextinFile was always null/undefined here -- an upload
through this page could never succeed even on PHP 7.4, and on PHP 8.1+
it also triggers "Passing null to parameter #1 ($to)... is deprecated".
$keyval was similarly used (e.g. in the hidden My_key form field)
before it was ever assigned, causing an "Undefined variable" warning
that could leak into an unquoted HTML attribute if display_errors is on.

Unlike bn_file_load_gom.php (a fresh-upload entry point that mints a
new random key), this page is only reached via a redirect from
modify_structure_learning.php with an existing My_key already in the
query string. Restored the commented-out block, adapted to read
$keyval from $_GET (matching how the rest of this file already does it
further down) instead of generating a new one, so $TextinFile is a
real path before the upload block runs.

Verified empirically against PHP 8.3.28: simulating an upload request
now correctly reaches move_uploaded_file() with a real path and falls
into the file's own pre-existing "Sorry, error uploading" handling
instead of silently failing on a null argument.

Reviewed by: Frederick M Muriithi <fredmanglis@gmail.com>

1 files changed, 13 insertions, 22 deletions

diff --git a/sourcecodes/bn_after_upload_gom.php b/sourcecodes/bn_after_upload_gom.php
index 63795759..d06954fd 100644
--- a/sourcecodes/bn_after_upload_gom.php
+++ b/sourcecodes/bn_after_upload_gom.php
@@ -21,28 +21,19 @@ $UploadValue="NO";
 $TextFile=$_FILES["MyFile"]["name"];
 
 
-/////////////Generate a random key/////////////////////
-//$alphas=array();
-//$alphas = array_merge(range('A', 'Z'), range('a', 'z'));
-
-//$al1=rand(0,51);
-//$al2=rand(0,51);
-//$al3=rand(0,51);
-
-//$alpha="$alphas[$al1]"."$alphas[$al2]"."$alphas[$al3]";
-//$keyval=$alpha;
-
-
-//if($_POST["My_key"]!="")
-//  $keyval=$_POST["My_key"];
-//  $keyval=valid_keyval($keyval);
-
-//$sid=$keyval."continuous_input";
-////$dir="./data/";
-//$dir="/tmp/bnw/";
-//$input_table_file="./data/".$keyval."input_table.txt";
-
-//$TextinFile=$dir.$sid."_orig.txt";
+/////////////Reuse the key established by the calling page/////////////////////
+// Unlike bn_file_load_gom.php (a fresh upload entry point that mints a new
+// random key), this page is only reached via a redirect from
+// modify_structure_learning.php with an existing My_key in the query string,
+// so $keyval is read from $_GET here instead of being generated.
+$keyval=valid_keyval($_GET["My_key"]);
+
+$sid=$keyval."continuous_input";
+//$dir="./data/";
+$dir="/tmp/bnw/";
+$input_table_file="./data/".$keyval."input_table.txt";
+
+$TextinFile=$dir.$sid."_orig.txt";
 
 
 if(isset($_POST["searchkey"]))