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The following commit(s) were added to refs/heads/master by this push:
new 749e09b PDFBOX-6162: handle shared symbol context properly
749e09b is described below
commit 749e09b774b85076bb9edd42583ded5a63f1d20f
Author: Maruan Sahyoun <[email protected]>
AuthorDate: Fri Apr 24 11:25:05 2026 +0200
PDFBOX-6162: handle shared symbol context properly
---
.../pdfbox/jbig2/segments/SymbolDictionary.java | 84 ++++++++++++++++------
.../org/apache/pdfbox/jbig2/SerenityTests.java | 3 +-
2 files changed, 64 insertions(+), 23 deletions(-)
diff --git
a/src/main/java/org/apache/pdfbox/jbig2/segments/SymbolDictionary.java
b/src/main/java/org/apache/pdfbox/jbig2/segments/SymbolDictionary.java
index 5cddb11..48f2eab 100644
--- a/src/main/java/org/apache/pdfbox/jbig2/segments/SymbolDictionary.java
+++ b/src/main/java/org/apache/pdfbox/jbig2/segments/SymbolDictionary.java
@@ -107,6 +107,8 @@ public class SymbolDictionary implements Dictionary
protected CX cxIAID;
private int sbSymCodeLen;
+ SymbolDictionary lastSymbolDictionary;
+
public SymbolDictionary()
{
}
@@ -129,7 +131,6 @@ public class SymbolDictionary implements Dictionary
setInSyms();
boolean isContextAdopted = false;
- SymbolDictionary lastSymbolDictionary = null;
SegmentHeader[] rtSegments = segmentHeader.getRtSegments();
@@ -145,8 +146,6 @@ public class SymbolDictionary implements Dictionary
if (isCodingContextUsed &&
lastSymbolDictionary.isCodingContextRetained)
{
- /* 7.4.2.2 3) */
- adoptRetainedCodingContexts(lastSymbolDictionary);
isContextAdopted = true;
}
break;
@@ -296,7 +295,7 @@ public class SymbolDictionary implements Dictionary
private void adoptRetainedCodingContexts(final SymbolDictionary sd) throws
InvalidHeaderValueException
{
validateContextValues(sd);
- this.cx = sd.cx;
+ this.cx = sd.cx.copy();
}
/**
@@ -376,6 +375,29 @@ public class SymbolDictionary implements Dictionary
}
}
+ private void ensureBitmapCxInitialized() throws
InvalidHeaderValueException, IOException
+ {
+ if (cx != null)
+ {
+ return;
+ }
+
+ if (isCodingContextUsed)
+ {
+ if (lastSymbolDictionary == null)
+ {
+ throw new InvalidHeaderValueException(
+ "Coding context reuse requested but no previous dictionary
available");
+ }
+
+ adoptRetainedCodingContexts(lastSymbolDictionary);
+ }
+ else
+ {
+ resetBitmapCodingStatistics();
+ }
+ }
+
/**
* 6.5.5 Decoding the symbol dictionary
*
@@ -387,19 +409,23 @@ public class SymbolDictionary implements Dictionary
{
if (null == exportSymbols)
{
+ ensureBitmapCxInitialized();
if (useRefinementAggregation)
sbSymCodeLen = getSbSymCodeLen();
- if (!isHuffmanEncoded)
- {
- if (!isCodingContextUsed)
- {
- resetBitmapCodingStatistics();
- }
+ if (!isHuffmanEncoded) {
resetIntegerCoderStatistics();
}
+ // decodes all referred segments including lastSymbolDictionary
+ setSymbolsArray();
+
+ // Now safe: lastSymbolDictionary was decoded by setSymbolsArray
above
+ if (!isHuffmanEncoded && isCodingContextUsed) {
+ adoptRetainedCodingContexts(lastSymbolDictionary);
+ }
+
/* 6.5.5 1) */
newSymbols = new Bitmap[amountOfNewSymbols];
@@ -410,8 +436,6 @@ public class SymbolDictionary implements Dictionary
newSymbolsWidths = new int[amountOfNewSymbols];
}
- setSymbolsArray();
-
/* 6.5.5 3) */
int heightClassHeight = 0;
amountOfDecodedSymbols = 0;
@@ -715,16 +739,37 @@ public class SymbolDictionary implements Dictionary
}
}
+ /**
+ * Decodes a new symbol using the provided parameters.
+ *
+ * @param symWidth The width of the symbol.
+ * @param hcHeight The height of the symbol.
+ * @param ibo The input bitmap object.
+ * @param rdx The x-offset for refinement.
+ * @param rdy The y-offset for refinement.
+ * @throws IllegalStateException if {@code cx} or {@code
arithmeticDecoder} is not initialized.
+ * @throws IOException if an I/O error occurs during decoding.
+ * @throws InvalidHeaderValueException if an invalid header value is
encountered.
+ * @throws IntegerMaxValueException if an integer value exceeds its
maximum allowed value
+ *
+ */
private void decodeNewSymbols(final int symWidth, final int hcHeight,
final Bitmap ibo,
final int rdx, final int rdy)
throws IOException, InvalidHeaderValueException,
IntegerMaxValueException
{
- if (arithmeticDecoder == null) {
- arithmeticDecoder = new ArithmeticDecoder(subInputStream);
+ // cx (bitmap coding context) must already be initialized via
ensureBitmapCxInitialized()
+ // in getDictionary(). It is required by
GenericRefinementRegionDecodingProcedure.decode
+ // and provides the arithmetic decoder statistics for bitmap decoding.
+ if (cx == null)
+ {
+ throw new IllegalStateException("CX not initialized (bug in
initialization order)");
}
- if (cx == null) {
- cx = new CX(65536, 1);
+ // arithmeticDecoder must already be initialized for the current
bitstream context.
+ // It is required by GenericRefinementRegionDecodingProcedure.decode
and is
+ // normally set during segment decoding (e.g., refinement or
integer-coded paths).
+ if (arithmeticDecoder == null) {
+ throw new IllegalStateException("ArithmeticDecoder not
initialized");
}
// Parameters as shown in Table 18, page 36
@@ -897,12 +942,9 @@ public class SymbolDictionary implements Dictionary
{
long exRunLength;
- if (isHuffmanEncoded)
- {
+ if (isHuffmanEncoded) {
exRunLength =
StandardTables.getTable(1).decode(subInputStream);
- }
- else
- {
+ } else {
exRunLength = iDecoder.decode(cxIAEX);
}
diff --git a/src/test/java/org/apache/pdfbox/jbig2/SerenityTests.java
b/src/test/java/org/apache/pdfbox/jbig2/SerenityTests.java
index 279d579..4a709b9 100644
--- a/src/test/java/org/apache/pdfbox/jbig2/SerenityTests.java
+++ b/src/test/java/org/apache/pdfbox/jbig2/SerenityTests.java
@@ -60,8 +60,7 @@ public class SerenityTests
{
String name = file.getName();
// Files that are not properly decoded yet
- if (name.equals("bitmap-refine-template1-tpgron.jbig2") ||
- name.equals("bitmap-symbol-context-reuse.jbig2"))
+ if (name.equals("bitmap-refine-template1-tpgron.jbig2"))
{
continue;
}
