[FOP-2920] [PATCH] Surrogate pair edge-case causes java.lang.ArrayIndexOutOfBoundsException

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.5
• Fix Version/s: 2.9
• Component/s: renderer/pdf
• Environment: macOS Mojave ; java version "1.8.0_192-ea" ; Java(TM) SE Runtime Environment (build 1.8.0_192-ea-b04) ; Java HotSpot(TM) 64-Bit Server VM (build 25.192-b04, mixed mode)
• Assignee: Simon Steiner
• Reporter: Kelly H Wilkerson
• Created: 13/Mar/20 16:26
• Updated: 01/Aug/23 10:31
• Resolved: 14/Jun/23 13:00

Description

fop-core/src/main/java/org/apache/fop/pdf/PDFToUnicodeCMap.java writeBFCharEntries runs through the codepoint entries in sections of 100 at a time. It looks like there's an edge case here where the last entry in the section is a surrogate pair.

 

Here's my steps to reproduce from the latest trunk:

java -cp fop/target/fop-2.5.0-SNAPSHOT.jar:fop/lib/commons-logging-1.0.4.jar:fop/lib/commons-io-1.3.1.jar:fop/lib/xmlgraphics-commons-svn-trunk.jar org.apache.fop.fonts.apps.TTFReader TwitterColorEmoji-SVGinOT.ttf twe.xml

java -cp fop/target/fop-2.5.0-SNAPSHOT.jar:fop/lib/commons-logging-1.0.4.jar:fop/lib/commons-io-1.3.1.jar:fop/lib/xmlgraphics-commons-svn-trunk.jar:fop/lib/batik-all-1.11.0-SNAPSHOT.jar org.apache.fop.cli.Main -c twe_userconfig.xml -xsl twe_template.fo -xml fail.xml -pdf fail.pdf

 

Here's the temporary way I resolved it for my own build:

 

index ee773dcec..37c21803e 100644
— a/fop-core/src/main/java/org/apache/fop/pdf/PDFToUnicodeCMap.java
+++ b/fop-core/src/main/java/org/apache/fop/pdf/PDFToUnicodeCMap.java
@@ -128,6 +128,18 @@ public class PDFToUnicodeCMap extends PDFCMap {
while (partOfRange(charArray, charIndex))

{ charIndex++; }

/*

• If this entry is going to overflow the entriesThisSection
• array, then don't use it. This happens if there are
• non-pair entries in the table mixed with pair entries.
  */
  if (Character.codePointAt(charArray, charIndex) > 0xFFFF
  && i+1 >= entriesThisSection) { entriesThisSection--; break; }

writer.write("<" + padCharIndex(charIndex) + "> ");

if (Character.codePointAt(charArray, charIndex) > 0xFFFF) {