Handle ranges that "overflow" the last byte in CMap.mapBfRange (bug 1627427)

test/pdfs/.gitignore

@@ -338,6 +338,7 @@
 !noembed-jis7.pdf
 !issue12504.pdf
 !noembed-eucjp.pdf
+!bug1627427_reduced.pdf
 !noembed-sjis.pdf
 !vertical.pdf
 !issue13343.pdf

test/test_manifest.json

@@ -3022,6 +3022,13 @@
        "rounds": 1,
        "type": "eq"
     },
+    {  "id": "bug1627427",
+       "file": "pdfs/bug1627427_reduced.pdf",
+       "md5": "3ff75fcf455af49803f0f04eb071bdc3",
+       "link": false,
+       "rounds": 1,
+       "type": "text"
+    },
     {  "id": "issue8586",
        "file": "pdfs/issue8586.pdf",
        "md5": "16b5230364017d3b0d2d65978eb35816",

test/unit/api_spec.js

@@ -1757,6 +1757,22 @@ sources, for full support with Dvips.`)
       await loadingTask.destroy();
     });
 
+    it("gets text content, with beginbfrange operator handled correctly (bug 1627427)", async function () {
+      const loadingTask = getDocument(
+        buildGetDocumentParams("bug1627427_reduced.pdf")
+      );
+      const pdfDoc = await loadingTask.promise;
+      const pdfPage = await pdfDoc.getPage(1);
+      const { items } = await pdfPage.getTextContent();
+      const text = mergeText(items);
+
+      expect(text).toEqual(
+        "침하게 흐린 품이 눈이 올 듯하더니 눈은 아니 오고 얼다가 만 비가 추"
+      );
+
+      await loadingTask.destroy();
+    });
+
     it("gets empty structure tree", async function () {
       const tree = await page.getStructTree();