From 10a0ea20acf1a190855d8fc5a25c9e80df71ee2a Mon Sep 17 00:00:00 2001
From: Mikhail Golenkov <mikhailgolenkov@catalyst-au.net>
Date: Wed, 11 Nov 2020 10:49:58 +1100
Subject: [PATCH] MDL-70117 dataformat_pdf: Fix content overflow when headers
 are involved

---
 dataformat/pdf/classes/writer.php | 43 ++++++++++++++++++++-----------
 1 file changed, 28 insertions(+), 15 deletions(-)

diff --git a/dataformat/pdf/classes/writer.php b/dataformat/pdf/classes/writer.php
index 3f916b1a59d..a4b2127bfc0 100644
--- a/dataformat/pdf/classes/writer.php
+++ b/dataformat/pdf/classes/writer.php
@@ -90,7 +90,7 @@ class writer extends \core\dataformat\base {
         $this->colwidth = $pagewidth / count($columns);
         $this->columns = $columns;
 
-        $this->print_heading();
+        $this->print_heading($this->pdf);
     }
 
     /**
@@ -137,10 +137,12 @@ class writer extends \core\dataformat\base {
             $pdf2->startTransaction();
             $numpages = $pdf2->getNumPages();
             $pdf2->AddPage('L');
+            $this->print_heading($pdf2);
             $pdf2->writeHTMLCell($this->colwidth, 0, '', '', $cell, 1, 1, false, true, 'L');
             $pagesadded = $pdf2->getNumPages() - $numpages;
-            $pageheight = $pdf2->getPageHeight() - $pdf2->getMargins()['top'] - $pdf2->getMargins()['bottom'];
-            $cellheight = ($pagesadded - 1) * $pageheight + $pdf2->getLastH();
+            $margins = $pdf2->getMargins();
+            $pageheight = $pdf2->getPageHeight() - $margins['top'] - $margins['bottom'];
+            $cellheight = ($pagesadded - 1) * $pageheight + $pdf2->getY() - $margins['top'] - $this->get_heading_height();
             $rowheight = max($rowheight, $cellheight);
             $pdf2->rollbackTransaction();
         }
@@ -149,7 +151,7 @@ class writer extends \core\dataformat\base {
         if ($this->pdf->getNumPages() > 1 &&
                 ($this->pdf->GetY() + $rowheight + $margins['bottom'] > $this->pdf->getPageHeight())) {
             $this->pdf->AddPage('L');
-            $this->print_heading();
+            $this->print_heading($this->pdf);
         }
 
         // Get the last key for this record.
@@ -186,25 +188,36 @@ class writer extends \core\dataformat\base {
     }
 
     /**
-     * Prints the heading row.
+     * Prints the heading row for a given PDF.
+     *
+     * @param \pdf $pdf A pdf to print headings in
      */
-    private function print_heading() {
-        $fontfamily = $this->pdf->getFontFamily();
-        $fontstyle = $this->pdf->getFontStyle();
-        $this->pdf->SetFont($fontfamily, 'B');
-        $rowheight = 0;
-        foreach ($this->columns as $columns) {
-            $rowheight = max($rowheight, $this->pdf->getStringHeight($this->colwidth, $columns, false, true, '', 1));
-        }
+    private function print_heading(\pdf $pdf) {
+        $fontfamily = $pdf->getFontFamily();
+        $fontstyle = $pdf->getFontStyle();
+        $pdf->SetFont($fontfamily, 'B');
 
         $total = count($this->columns);
         $counter = 1;
         foreach ($this->columns as $columns) {
             $nextposition = ($counter == $total) ? 1 : 0;
-            $this->pdf->Multicell($this->colwidth, $rowheight, $columns, 1, 'C', true, $nextposition);
+            $pdf->Multicell($this->colwidth, $this->get_heading_height(), $columns, 1, 'C', true, $nextposition);
             $counter++;
         }
 
-        $this->pdf->SetFont($fontfamily, $fontstyle);
+        $pdf->SetFont($fontfamily, $fontstyle);
+    }
+
+    /**
+     * Returns the heading height.
+     *
+     * @return int
+     */
+    private function get_heading_height() {
+        $height = 0;
+        foreach ($this->columns as $columns) {
+            $height = max($height, $this->pdf->getStringHeight($this->colwidth, $columns, false, true, '', 1));
+        }
+        return $height;
     }
 }