Repair CFF fonts if stem hints are in wrong order

src/core/cff_parser.js

@@ -539,6 +539,16 @@ var CFFParser = (function CFFParserClosure() {
         if (validationCommand) {
           if (validationCommand.stem) {
             state.hints += stackSize >> 1;
+            if (value === 3 || value === 23) {
+              // vstem or vstemhm.
+              state.hasVStems = true;
+            } else if (state.hasVStems && (value === 1 || value === 18)) {
+              // Some browsers don't draw glyphs that specify vstems before
+              // hstems. As a workaround, replace hstem (1) and hstemhm (18)
+              // with a pointless vstem (3) or vstemhm (23).
+              warn('CFF stem hints are in wrong order');
+              data[j - 1] = (value === 1) ? 3 : 23;
+            }
           }
           if ('min' in validationCommand) {
             if (!state.undefStack && stackSize < validationCommand.min) {
@@ -599,6 +609,7 @@ var CFFParser = (function CFFParserClosure() {
           firstStackClearing: true,
           seac: null,
           width: null,
+          hasVStems: false,
         };
         var valid = true;
         var localSubrToUse = null;

test/pdfs/.gitignore

@@ -264,6 +264,7 @@
 !annotation-tx3.pdf
 !coons-allflags-withfunction.pdf
 !tensor-allflags-withfunction.pdf
+!issue10084_reduced.pdf
 !issue4246.pdf
 !issue4461.pdf
 !issue4573.pdf

test/test_manifest.json

@@ -2750,6 +2750,12 @@
        "type": "text",
        "about": "Note that the text layer seems to be off to the right."
     },
+    {  "id": "issue10084",
+       "file": "pdfs/issue10084_reduced.pdf",
+       "md5": "ae37cf36f2e319688c608e4086836824",
+       "rounds": 1,
+       "type": "eq"
+    },
     {  "id": "issue4890",
        "file": "pdfs/issue4890.pdf",
        "md5": "1666feb4cd26318c2bdbea6a175dce87",