Fix: prevent scale vs page loop in pngx PDF viewer (#13406)

src-ui/src/app/components/common/pdf-viewer/pdf-viewer.component.spec.ts

@@ -129,13 +129,25 @@ describe('PngxPdfViewerComponent', () => {
     ;(component as any).applyScale()
     expect(viewer.currentScaleValue).toBe(PdfZoomScale.PageFit)
     expect(viewer.currentScale).toBe(2)
+  })
 
+  it('does not reapply scale for page-only changes', async () => {
+    await initComponent()
+
+    const pdf = (component as any).pdf as { numPages: number }
+    pdf.numPages = 3
+    const viewer = (component as any).pdfViewer as PDFViewer
+    viewer.setDocument(pdf)
     const applyScaleSpy = jest.spyOn(component as any, 'applyScale')
     component.page = 2
-    ;(component as any).lastViewerPage = 2
-    ;(component as any).applyViewerState()
+
+    component.ngOnChanges({
+      page: new SimpleChange(1, 2, false),
+    })
+
+    expect(viewer.currentPageNumber).toBe(2)
     expect((component as any).lastViewerPage).toBeUndefined()
-    expect(applyScaleSpy).toHaveBeenCalled()
+    expect(applyScaleSpy).not.toHaveBeenCalled()
   })
 
   it('does not reset the viewer when it is already on the requested page', async () => {

src-ui/src/app/components/common/pdf-viewer/pdf-viewer.component.ts

@@ -116,7 +116,10 @@ export class PngxPdfViewerComponent
       changes['zoomScale'] ||
       changes['rotation']
     ) {
-      this.applyViewerState()
+      // Prevent loop with page / scale application see https://github.com/paperless-ngx/paperless-ngx/issues/13404
+      this.applyViewerState(
+        !!(changes['zoom'] || changes['zoomScale'] || changes['rotation'])
+      )
     }
 
     if (changes['searchQuery']) {
@@ -240,7 +243,7 @@ export class PngxPdfViewerComponent
     }
   }
 
-  private applyViewerState(): void {
+  private applyViewerState(applyScale = true): void {
     if (!this.pdfViewer) {
       return
     }
@@ -264,7 +267,7 @@ export class PngxPdfViewerComponent
     if (this.page === this.lastViewerPage) {
       this.lastViewerPage = undefined
     }
-    if (hasPages) {
+    if (hasPages && applyScale) {
       this.applyScale()
     }
     this.dispatchFindIfReady()

src/documents/mail.py

@@ -36,6 +36,9 @@ def send_email(
 
     TODO: re-evaluate this pending https://code.djangoproject.com/ticket/35581 / https://github.com/django/django/pull/18966
     """
+    if "\r" in subject or "\n" in subject:
+        subject = " ".join(line.strip(" \t") for line in subject.splitlines())
+
     email = EmailMessage(
         subject=subject,
         body=body,

src/documents/management/commands/document_importer.py

@@ -386,10 +386,19 @@ class Command(CryptMixin, PaperlessCommand):
                 raise DeserializationError(
                     f"{model.__name__} has no updatable fields; PK-only models are not supported by the importer",
                 )
+            # MySQL/MariaDB support upserts via ON DUPLICATE KEY UPDATE but,
+            # unlike PostgreSQL/SQLite, cannot target a specific unique field
+            # for the conflict -- passing unique_fields there raises
+            # NotSupportedError.
+            unique_fields = (
+                [model._meta.pk.attname]
+                if connection.features.supports_update_conflicts_with_target
+                else None
+            )
             model.objects.bulk_create(  # type: ignore[attr-defined]
                 instances,
                 update_conflicts=True,
-                unique_fields=[model._meta.pk.attname],
+                unique_fields=unique_fields,
                 update_fields=update_fields,
             )
             loaded_models.add(model)

src/documents/tests/test_api_email.py

@@ -75,7 +75,7 @@ class TestEmail(DirectoriesMixin, SampleDirMixin, APITestCase):
                 {
                     "documents": [self.doc1.pk, self.doc2.pk],
                     "addresses": "hello@paperless-ngx.com,test@example.com",
-                    "subject": "Bulk email test",
+                    "subject": "Bulk email\n test",
                     "message": "Here are your documents",
                 },
             ),