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#556 PICTImageReaderSpi no longer claim to decode known formats

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This commit is contained in:
Harald Kuhr
2020-08-07 16:31:29 +02:00
parent 49c7cd1979
commit bda6544a5f
3 changed files with 102 additions and 10 deletions
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imageio/imageio-pict/src/main/java/com/twelvemonkeys/imageio/plugins/pict/PICTImageReaderSpi.java
+64 -8
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@@ -60,6 +60,13 @@ public final class PICTImageReaderSpi extends ImageReaderSpiBase {
}
ImageInputStream stream = (ImageInputStream) pSource;
// As PICT format don't have good magic and our method often gives false positives,
// so we'll need to check for other known formats (BMP, GIF, JPEG, PNG, PSD, TIFF) first
if (isOtherFormat(stream)) {
return false;
}
stream.mark();
try {
@@ -68,13 +75,12 @@ public final class PICTImageReaderSpi extends ImageReaderSpiBase {
return true;
}
else {
// Skip header 512 bytes for file-based streams
stream.reset();
// We need to set mark again, to make sure the reset call in
// We need to reset AND set mark again, to make sure the reset call in
// the finally block will not consume existing marks
stream.reset();
stream.mark();
// Skip header 512 bytes for file-based streams
skipNullHeader(stream);
}
@@ -88,6 +94,60 @@ public final class PICTImageReaderSpi extends ImageReaderSpiBase {
}
}
// TODO: Candidate util method.
// Might need to be able to exclude some formats
// Might need to return the format matched...
static boolean isOtherFormat(final ImageInputStream stream) throws IOException {
stream.mark();
try {
byte[] signature = new byte[8];
stream.readFully(signature);
// BMP: off: 0, len: 2, magic: 'B', 'M'
// GIF: off: 0, len: 6, magic: 'G', 'I', 'F', '8', ('7' | '9'), 'a' (use only "GIF8"?)
// JPEG: off 0, len: 2, magic: 0xffd8 (SOI marker)
// PNG: off: 0, len: 8, magic: 0x89, 'P', 'N', 'G', 0x0d0a1a0a
// PSD: off: 0, len: 4, magic: '8', 'B', 'P', 'S'
// TIFF: off: 0, len: 4, magic: ('I', 'I', 0x00, (0x42 | 0x43)) | ('M', 'M', (0x42 | 0x43), 0x00) (43 is bigTiff)
if (signature[0] == 'B' && signature[1] == 'M') {
// BMP
return true;
}
if (signature[0] == 'G' && signature[1] == 'I' && signature[2] == 'F' && signature[3] == '8'
&& (signature[4] == '7' || signature[4] == '9') && signature[5] == 'a') {
// GIF
return true;
}
if (signature[0] == (byte) 0xFF && signature[1] == (byte) 0xD8 && signature[2] == (byte) 0xFF) {
// JPEG
return true;
}
if (signature[0] == (byte) 0x89 && signature[1] == 'P' && signature[2] == 'N' && signature[3] == 'G'
&& signature[4] == 0x0D && signature[5] == 0x0A && signature[6] == 0x1A && signature[7] == 0x0A) {
// PNG
return true;
}
if (signature[0] == '8' && signature[1] == 'B' && signature[2] == 'P' && signature[3] == 'S') {
// PSD
return true;
}
if ((signature[0] == 'I' && signature[1] == 'I' && (signature[2] == 42 || signature[2] == 43) && signature[3] == 0x00)
|| signature[0] == 'M' && signature[1] == 'M' && signature[2] == 0x00 && (signature[3] == 42 || signature[3] == 43)) {
// TIFF/BigTIFF
return true;
}
}
catch (EOFException ignore) {
// Can't be any of the formats
}
finally {
stream.reset();
}
return false;
}
static void skipNullHeader(final ImageInputStream pStream) throws IOException {
// NOTE: Only skip if FILE FORMAT, not needed for Mac OS DnD
// Spec says "platform dependent", may not be all nulls..
@@ -102,10 +162,6 @@ public final class PICTImageReaderSpi extends ImageReaderSpiBase {
// Sanity check bounding box
int y1 = pStream.readUnsignedShort();
int x1 = pStream.readUnsignedShort();
// TODO: Figure out if frame can ever start at negative bounds...
// if (x1 != 0 || y1 != 0) {
// return false;
// }
int y2 = pStream.readUnsignedShort();
int x2 = pStream.readUnsignedShort();