Fixes canvas state after smask group ends.

src/display/canvas.js

@@ -973,6 +973,7 @@ var CanvasGraphics = (function CanvasGraphicsClosure() {
 
       composeSMask(this.ctx, this.current.activeSMask, groupCtx);
       this.ctx.restore();
+      copyCtxState(groupCtx, this.ctx);
     },
     save: function CanvasGraphics_save() {
       this.ctx.save();

test/pdfs/issue6032.pdf.link

@@ -0,0 +1 @@
+http://web.archive.org/web/20151203200805/http://www.barkleyus.com/files/moonshot_techroadmap_poster.pdf

test/test_manifest.json

@@ -1323,6 +1323,14 @@
        "link": false,
        "type": "eq"
     },
+    {
+      "id": "issue6032",
+      "file": "pdfs/issue6032.pdf",
+      "md5": "88b4cc989f5a1e072b992dec5635e83c",
+      "rounds": 1,
+      "link": true,
+      "type": "eq"
+    },
     {
       "id": "issue6019-text",
       "file": "pdfs/issue6019.pdf",