From 3891f57755f259c22e1b88d3118b7f3e4ac80bc3 Mon Sep 17 00:00:00 2001
From: Mike Kroutikov <mkroutikov@innodata.com>
Date: Mon, 12 Jan 2015 01:37:54 +0000
Subject: [PATCH] attemp to fix disappearing chars bug by allowing to redefine
 only valid glyph names

---
 poppler/GfxFont.cc | 30 +++++++++++++++++++++++++-----
 1 file changed, 25 insertions(+), 5 deletions(-)

diff --git a/poppler/GfxFont.cc b/poppler/GfxFont.cc
index 39f026a..900bd58 100644
--- a/poppler/GfxFont.cc
+++ b/poppler/GfxFont.cc
@@ -1026,6 +1026,21 @@ static GBool testForNumericNames(Dict *fontDict, GBool hex) {
   return numeric;
 }
 
+GBool isValidGlyphName(char const **names, char const *oldName, char const *name) {
+
+  // allow override of empty encoding slots with anything
+  if (!oldName || strcmp(oldName, ".notdef") == 0) return gTrue;
+
+  // .notdef is implicitly valid glyph name
+  if (strcmp(name, ".notdef") == 0) return gTrue;
+
+  for(int i = 0; i < 256; i++) {
+    if (names[i] && strcmp(names[i], name) == 0) return gTrue;
+  }
+
+  return gFalse;
+}
+
 Gfx8BitFont::Gfx8BitFont(XRef *xref, const char *tagA, Ref idA, GooString *nameA,
 			 GfxFontType typeA, Ref embFontIDA, Dict *fontDict):
   GfxFont(tagA, idA, nameA, typeA, embFontIDA) {
@@ -1169,6 +1184,9 @@ Gfx8BitFont::Gfx8BitFont(XRef *xref, const char *tagA, Ref idA, GooString *nameA
   //        - others --> StandardEncoding
   // and then add a list of differences (if any) from
   // FontDict.Encoding.Differences.
+  // 
+  // When merging encodings make sure that glyph name exists
+  // in the font program (works only for 8bit type1 embedded fonts)
 
   // check FontDict for base encoding
   hasEncoding = gFalse;
@@ -1304,11 +1322,13 @@ Gfx8BitFont::Gfx8BitFont(XRef *xref, const char *tagA, Ref idA, GooString *nameA
 	  code = obj3.getInt();
 	} else if (obj3.isName()) {
 	  if (code >= 0 && code < 256) {
-	    if (encFree[code]) {
-	      gfree(enc[code]);
-	    }
-	    enc[code] = copyString(obj3.getName());
-	    encFree[code] = gTrue;
+            if (!baseEncFromFontFile || type != fontType1 || isValidGlyphName(baseEnc, enc[code], obj3.getName())) {
+	      if (encFree[code]) {
+	        gfree(enc[code]);
+	      }
+	      enc[code] = copyString(obj3.getName());
+	      encFree[code] = gTrue;
+            }
 	  }
 	  ++code;
 	} else {
-- 
1.9.1