Backport of the upstream commit:

From 2e82fa00466ae525339754bb3ab0a0474a31d4bd Mon Sep 17 00:00:00 2001
From: Michael Adams <mdadams@ece.uvic.ca>
Date: Wed, 19 Oct 2016 17:57:40 -0700
Subject: [PATCH] Fixed an integral type promotion problem by adding a
 JAS_CAST. Modified the jpc_tsfb_synthesize function so that it will be a noop
 for an empty sequence (in order to avoid dereferencing a null pointer).

diff -pruN jasper-1.900.1.orig/src/libjasper/include/jasper/jas_math.h jasper-1.900.1/src/libjasper/include/jasper/jas_math.h
--- jasper-1.900.1.orig/src/libjasper/include/jasper/jas_math.h	2017-03-31 14:08:18.000000000 +0200
+++ jasper-1.900.1/src/libjasper/include/jasper/jas_math.h	2017-03-31 14:09:06.000000000 +0200
@@ -115,6 +115,24 @@ extern "C" {
   ((1 << (n)) - 1)
 
 /******************************************************************************\
+*
+\******************************************************************************/
+
+__attribute__((no_sanitize("undefined")))
+inline static jas_int_asr(int x, int n)
+{
+	assert(n >= 0);
+	return x >> n;
+}
+
+__attribute__((no_sanitize("undefined")))
+inline static jas_int_asl(int x, int n)
+{
+	assert(n >= 0);
+	return x << n;
+}
+
+/******************************************************************************\
 * Safe integer arithmetic (i.e., with overflow checking).
 \******************************************************************************/
 
diff -pruN jasper-1.900.1.orig/src/libjasper/include/jasper/jas_seq.h jasper-1.900.1/src/libjasper/include/jasper/jas_seq.h
--- jasper-1.900.1.orig/src/libjasper/include/jasper/jas_seq.h	2007-01-19 22:43:04.000000000 +0100
+++ jasper-1.900.1/src/libjasper/include/jasper/jas_seq.h	2017-03-31 14:09:06.000000000 +0200
@@ -154,6 +154,9 @@ typedef jas_matrix_t jas_seq_t;
 #define jas_matrix_numcols(matrix) \
 	((matrix)->numcols_)
 
+#define jas_matrix_size(matrix) \
+	(jas_matrix_width(matrix) * jas_matrix_height(matrix))
+
 /* Get a matrix element. */
 #define jas_matrix_get(matrix, i, j) \
 	((matrix)->rows_[i][j])
@@ -269,6 +272,8 @@ jas_matrix_t *jas_seq2d_create(int xstar
 	((s)->xstart_ = (x), (s)->ystart_ = (y), \
 	  (s)->xend_ = (s)->xstart_ + (s)->numcols_, \
 	  (s)->yend_ = (s)->ystart_ + (s)->numrows_)
+#define jas_seq2d_size(s) \
+	(jas_seq2d_width(s) * jas_seq2d_height(s))
 
 void jas_seq2d_bindsub(jas_matrix_t *s, jas_matrix_t *s1, int xstart,
   int ystart, int xend, int yend);
diff -pruN jasper-1.900.1.orig/src/libjasper/jpc/jpc_dec.c jasper-1.900.1/src/libjasper/jpc/jpc_dec.c
--- jasper-1.900.1.orig/src/libjasper/jpc/jpc_dec.c	2017-03-31 14:08:18.000000000 +0200
+++ jasper-1.900.1/src/libjasper/jpc/jpc_dec.c	2017-03-31 14:09:06.000000000 +0200
@@ -1805,6 +1805,13 @@ static void jpc_undo_roi(jas_matrix_t *x
 	bool warn;
 	uint_fast32_t mask;
 
+	if (roishift < 0) {
+		/* We could instead return an error here. */
+		/* I do not think it matters much. */
+		jas_eprintf("warning: forcing negative ROI shift to zero "
+		  "(bitstream is probably corrupt)\n");
+		roishift = 0;
+	}
 	if (roishift == 0 && bgshift == 0) {
 		return;
 	}
@@ -1823,7 +1830,7 @@ static void jpc_undo_roi(jas_matrix_t *x
 			} else {
 				/* We are dealing with non-ROI (i.e., background) data. */
 				mag <<= bgshift;
-				mask = (1 << numbps) - 1;
+				mask = (JAS_CAST(uint_fast32_t, 1) << numbps) - 1;
 				/* Perform a basic sanity check on the sample value. */
 				/* Some implementations write garbage in the unused
 				  most-significant bit planes introduced by ROI shifting.
diff -pruN jasper-1.900.1.orig/src/libjasper/jpc/jpc_tsfb.c jasper-1.900.1/src/libjasper/jpc/jpc_tsfb.c
--- jasper-1.900.1.orig/src/libjasper/jpc/jpc_tsfb.c	2007-01-19 22:43:07.000000000 +0100
+++ jasper-1.900.1/src/libjasper/jpc/jpc_tsfb.c	2017-03-31 14:09:06.000000000 +0200
@@ -148,7 +148,8 @@ int jpc_tsfb_analyze2(jpc_tsfb_t *tsfb,
 
 int jpc_tsfb_synthesize(jpc_tsfb_t *tsfb, jas_seq2d_t *a)
 {
-	return (tsfb->numlvls > 0) ? jpc_tsfb_synthesize2(tsfb,
+	return (tsfb->numlvls > 0 && jas_seq2d_size(a)) ?
+	  jpc_tsfb_synthesize2(tsfb,
 	  jas_seq2d_getref(a, jas_seq2d_xstart(a), jas_seq2d_ystart(a)),
 	  jas_seq2d_xstart(a), jas_seq2d_ystart(a), jas_seq2d_width(a),
 	  jas_seq2d_height(a), jas_seq2d_rowstep(a), tsfb->numlvls - 1) : 0;