fix: Write() keeps the left cell padding and the right margin when the cursor has been moved

- Write() measures the first line offset from the unpadded flow origin, so text started after setX() is inset by the left cell padding like text started at the margin.
- Require tc-lib-pdf ^8.73.5, which aligns an LTR right-aligned first line to the right margin instead of the cursor and resolves the font-relative CSS units (em, rem, ex, ch) against the real font size instead of the built-in defaults.
- Add regression tests for both cursor cases, with a wordBox() helper reading exact word positions via pdftotext -bbox.
- example_002: show that setX() moves where a Write() line starts without dropping the padding or moving the edge a right-aligned line is flush with.
- build: install mago 1.47.6 through Composer instead of the upstream installer script, and add the tag release workflow.

Author: nicolaasuni

composer.json

@@ -29,7 +29,7 @@
     "require": {
         "php": ">=8.2",
         "ext-curl": "*",
-        "tecnickcom/tc-lib-pdf": "^8.73"
+        "tecnickcom/tc-lib-pdf": "^8.73.5"
     },
     "require-dev": {
         "carthage-software/mago": "1.47.6",

examples/example_002.php

@@ -84,5 +84,21 @@
 
 // ---------------------------------------------------------
 
+// The cursor set by setX() only says where a line may start: it carries the
+// left cell padding like a line starting at the margin, and it does not move
+// the right margin a right aligned line is flush with.
+$pdf->setFont('times', '', 12);
+$pdf->Ln(10);
+
+$pdf->Write(0, 'left aligned from the left margin', '', 0, 'L', true);
+$pdf->setX(80);
+$pdf->Write(0, 'left aligned from setX(80)', '', 0, 'L', true);
+
+$pdf->Write(0, 'right aligned from the left margin', '', 0, 'R', true);
+$pdf->setX(80);
+$pdf->Write(0, 'right aligned from setX(80)', '', 0, 'R', true);
+
+// ---------------------------------------------------------
+
 //Close and output PDF document
 $pdf->Output('example_002.pdf', 'I');

tcpdf.php

@@ -3950,13 +3950,15 @@ public function Write(
         // (and through the following columns/pages inside the engine call).
         $incolumns = $this->inColumnMode();
         $region = $eng->page->getRegion();
-        $originx = $incolumns ? $region['RX'] : $this->lmargin;
+        $flowx = $incolumns ? $region['RX'] : $this->lmargin;
         $width = $incolumns ? $region['RW'] : $this->getPageWidth() - $this->rmargin - $this->lmargin;
         // Legacy wraps the lines inside the horizontal cell padding and
         // starts them at the padded edge.
-        $originx += $this->cellpadding['L'];
+        $originx = $flowx + $this->cellpadding['L'];
         $width = max(0.0, $width - $this->cellpadding['L'] - $this->cellpadding['R']);
-        $offset = max(0.0, $this->posx - $originx);
+        // The cursor carries the padding too, so it is measured from the
+        // unpadded flow origin.
+        $offset = max(0.0, $this->posx - $flowx);
 
         $styles = ['all' => ['lineWidth' => 0.0]];
         if ((bool) $_fill) {

test/TcpdfCellTest.php

@@ -112,4 +112,46 @@ public function testTextPlacesAtAbsolutePosition(): void
         $pdf->Text(25, 120, 'absolutely positioned');
         $this->assertStringContainsString('absolutely positioned', $this->extractText($pdf));
     }
+
+    public function testWriteAppliesTheLeftCellPaddingWhereverTheCursorIs(): void
+    {
+        $pdf = $this->newPdf();
+        $pdf->setFont('helvetica', '', 11);
+        $pdf->setMargins(20, 20, 20);
+        $pdf->setCellPaddings(1, 0, 1, 0);
+        $pdf->AddPage();
+
+        $pdf->Write(5, "first\n");
+        $pdf->setX(40.0);
+        $pdf->Write(5, "second\n");
+
+        $padding = $pdf->getCellPaddings()['L'];
+        $this->assertGreaterThan(0.0, $padding);
+
+        // Both lines start one left padding to the right of their cursor.
+        $topt = 72.0 / 25.4;
+        $margin = $this->wordBox($pdf, 'first');
+        $indented = $this->wordBox($pdf, 'second');
+        $this->assertEqualsWithDelta((20.0 + $padding) * $topt, $margin['xmin'], 0.01);
+        $this->assertEqualsWithDelta((40.0 + $padding) * $topt, $indented['xmin'], 0.01);
+    }
+
+    public function testWriteRightAlignsToTheRightMarginWhereverTheCursorIs(): void
+    {
+        $pdf = $this->newPdf();
+        $pdf->setFont('helvetica', '', 9);
+        $pdf->setMargins(11, 11, 11);
+        $pdf->AddPage();
+
+        $height = $pdf->getCellHeight($pdf->getFontSize());
+        $pdf->Write($height, 'alpha', '', false, 'R', true);
+        $pdf->setX(107.95);
+        $pdf->Write($height, 'bravo', '', false, 'R', true);
+
+        // The cursor limits where a right aligned line may start, it does not
+        // move the edge the line is aligned to.
+        $plain = $this->wordBox($pdf, 'alpha');
+        $moved = $this->wordBox($pdf, 'bravo');
+        $this->assertEqualsWithDelta($plain['xmax'], $moved['xmax'], 0.01);
+    }
 }

test/TcpdfTestCase.php

@@ -62,4 +62,39 @@ protected function pdfInfo(TCPDF $pdf): string
     {
         return $this->popplerTool('pdfinfo', $pdf);
     }
+
+    /**
+     * Return the bounding box in PDF points of the first word matching $word.
+     *
+     * @return array{xmin: float, xmax: float, ymin: float, ymax: float}
+     */
+    protected function wordBox(TCPDF $pdf, string $word): array
+    {
+        $out = $this->popplerTool('pdftotext', $pdf, '-bbox -');
+        $match = [];
+        $found = preg_match(
+            '/<word xMin="([\d.]+)" yMin="([\d.]+)" xMax="([\d.]+)" yMax="([\d.]+)">'
+            . preg_quote($word, '/')
+            . '<\/word>/',
+            $out,
+            $match,
+        );
+        $this->assertSame(1, $found, 'word "' . $word . '" must be present');
+
+        return [
+            'xmin' => $this->toFloat($match[1] ?? ''),
+            'ymin' => $this->toFloat($match[2] ?? ''),
+            'xmax' => $this->toFloat($match[3] ?? ''),
+            'ymax' => $this->toFloat($match[4] ?? ''),
+        ];
+    }
+
+    /**
+     * Parse a decimal number, defaulting to zero.
+     */
+    private function toFloat(string $value): float
+    {
+        $number = filter_var($value, FILTER_VALIDATE_FLOAT);
+        return $number === false ? 0.0 : $number;
+    }
 }