ghostscript/SOURCES/0001-Bug-701568-followup-Fix-RLE-compressor.patch

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2024-11-05 00:40:27 +00:00
From 3b2ad1f24d2e9705481f9feb6835aa3e851726ac Mon Sep 17 00:00:00 2001
From: Robin Watts <Robin.Watts@artifex.com>
Date: Thu, 12 Sep 2019 17:09:50 +0100
Subject: [PATCH] Bug 701568 followup: Fix RLE compressor.
The previous fix to the RLE compressor reveals an additional
existing issue to do with us not checking whether we have
space in the buffer to write the EOD byte.
Fixed here.
---
base/srle.c | 78 ++++++++++++++++++++++++++++++-----------------------
1 file changed, 45 insertions(+), 33 deletions(-)
diff --git a/base/srle.c b/base/srle.c
index 50de0d847..0c0186e04 100644
--- a/base/srle.c
+++ b/base/srle.c
@@ -59,7 +59,13 @@ enum {
state_gt_012,
/* -n bytes into a repeated run, n0 and n1 read. */
- state_lt_01
+ state_lt_01,
+
+ /* We have reached the end of data, but not written the marker. */
+ state_eod_unmarked,
+
+ /* We have reached the end of data, and written the marker. */
+ state_eod
};
#ifdef DEBUG_RLE
@@ -294,43 +300,49 @@ run_len_0_n0_read:
}
}
}
- }
- /* n1 is never valid here */
+ /* n1 is never valid here */
- if (last) {
- if (run_len == 0) {
- /* EOD */
- if (wlimit - q < 1) {
- ss->state = state_0;
- goto no_output_room;
- }
- } else if (run_len > 0) {
- /* Flush literal run + EOD */
- if (wlimit - q < run_len+2) {
- ss->state = state_0;
- goto no_output_room;
+ if (last) {
+ if (run_len == 0) {
+ /* EOD */
+ if (wlimit - q < 1) {
+ ss->state = state_0;
+ goto no_output_room;
+ }
+ } else if (run_len > 0) {
+ /* Flush literal run + EOD */
+ if (wlimit - q < run_len+2) {
+ ss->state = state_0;
+ goto no_output_room;
+ }
+ *++q = run_len;
+ memcpy(q+1, ss->literals, run_len);
+ q += run_len;
+ *++q = n0;
+ } else if (run_len < 0) {
+ /* Flush repeated run + EOD */
+ if (wlimit - q < 3) {
+ ss->state = state_0;
+ goto no_output_room;
+ }
+ *++q = 257+run_len; /* Repeated run */
+ *++q = n0;
}
- *++q = run_len;
- memcpy(q+1, ss->literals, run_len);
- q += run_len;
- *++q = n0;
- } else if (run_len < 0) {
- /* Flush repeated run + EOD */
- if (wlimit - q < 3) {
- ss->state = state_0;
+ case state_eod_unmarked:
+ if (wlimit - q < 1) {
+ ss->state = state_eod_unmarked;
goto no_output_room;
}
- *++q = 257+run_len; /* Repeated run */
- *++q = n0;
+ *++q = 128; /* EOD */
+ case state_eod:
+ ss->run_len = 0;
+ ss->state = state_0;
+ pr->ptr = p;
+ pw->ptr = q;
+ ss->record_left = rlimit - p;
+ debug_ate(pinit, p, qinit, q, EOFC);
+ return EOFC;
}
- *++q = 128; /* EOD */
- ss->run_len = 0;
- ss->state = state_0;
- pr->ptr = p;
- pw->ptr = q;
- ss->record_left = rlimit - p;
- debug_ate(pinit, p, qinit, q, EOFC);
- return EOFC;
}
/* Normal exit */
--
2.46.2