--- a/third_party/skia/src/gpu/ganesh/ops/AAHairLinePathRenderer.cpp
+++ b/third_party/skia/src/gpu/ganesh/ops/AAHairLinePathRenderer.cpp
@@ -681,6 +681,19 @@ void set_conic_coeffs(const SkPoint p[3],
     }
 }

+// On bloat_quad failure, fill the slot with degenerate offscreen vertices and
+// advance anyway -- mirrors the existing add_line() else-branch. The vertex
+// slot was already allocated and counted toward setIndexedPatterned in
+// onPrepareDraws; leaving the cursor unmoved would submit stale buffer
+// contents.
+static void backfill_degenerate_bezier(BezierVertex** vert) {
+    for (int i = 0; i < kQuadNumVertices; ++i) {
+        (*vert)[i].fPos.set(SK_ScalarMax, SK_ScalarMax);
+        (*vert)[i].fConic.fKLM[0] = (*vert)[i].fConic.fKLM[1] = (*vert)[i].fConic.fKLM[2] = 0;
+    }
+    *vert += kQuadNumVertices;
+}
+
 void add_conics(const SkPoint p[3],
                 const SkScalar weight,
                 const SkMatrix* toDevice,
@@ -689,6 +702,8 @@ void add_conics(const SkPoint p[3],
     if (bloat_quad(p, toDevice, toSrc, *vert)) {
         set_conic_coeffs(p, *vert, weight);
         *vert += kQuadNumVertices;
+    } else {
+        backfill_degenerate_bezier(vert);
     }
 }

@@ -720,6 +735,8 @@ void add_quads(const SkPoint p[3],
             set_uv_quad(choppedQuadPts, outVerts);
             memcpy(*vert, outVerts, kQuadNumVertices * sizeof(BezierVertex));
             *vert += kQuadNumVertices;
+        } else {
+            backfill_degenerate_bezier(vert);
         }
         --stepCount;
     }
@@ -729,6 +746,8 @@ void add_quads(const SkPoint p[3],
         set_uv_quad(&choppedQuadPts[2], outVerts);
         memcpy(*vert, outVerts, kQuadNumVertices * sizeof(BezierVertex));
         *vert += kQuadNumVertices;
+    } else {
+        backfill_degenerate_bezier(vert);
     }
 }