Fix CVE-2016-9601:

https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-9601
https://bugs.ghostscript.com/show_bug.cgi?id=697457

Patch copied from upstream source repository:

http://git.ghostscript.com/?p=jbig2dec.git;a=commitdiff;h=e698d5c11d27212aa1098bc5b1673a3378563092

From e698d5c11d27212aa1098bc5b1673a3378563092 Mon Sep 17 00:00:00 2001
From: Robin Watts <robin.watts@artifex.com>
Date: Mon, 12 Dec 2016 17:47:17 +0000
Subject: [PATCH] Squash signed/unsigned warnings in MSVC jbig2 build.

Also rename "new" to "new_dict", because "new" is a bad
variable name.
---
 jbig2.c             |  4 +--
 jbig2.h             |  8 +++---
 jbig2_generic.c     |  2 +-
 jbig2_halftone.c    | 24 ++++++++----------
 jbig2_huffman.c     | 10 ++++----
 jbig2_huffman.h     |  2 +-
 jbig2_image.c       | 32 +++++++++++------------
 jbig2_mmr.c         | 66 +++++++++++++++++++++++++-----------------------
 jbig2_page.c        |  6 ++---
 jbig2_priv.h        |  4 +--
 jbig2_segment.c     | 10 ++++----
 jbig2_symbol_dict.c | 73 +++++++++++++++++++++++++++--------------------------
 jbig2_symbol_dict.h |  6 ++---
 jbig2_text.c        | 16 ++++++------
 jbig2_text.h        |  2 +-
 15 files changed, 134 insertions(+), 131 deletions(-)

diff --git a/jbig2.c b/jbig2.c
index f729e29..e51380f 100644
--- a/jbig2.c
+++ b/jbig2.c
@@ -379,7 +379,7 @@ typedef struct {
 } Jbig2WordStreamBuf;
 
 static int
-jbig2_word_stream_buf_get_next_word(Jbig2WordStream *self, int offset, uint32_t *word)
+jbig2_word_stream_buf_get_next_word(Jbig2WordStream *self, size_t offset, uint32_t *word)
 {
     Jbig2WordStreamBuf *z = (Jbig2WordStreamBuf *) self;
     const byte *data = z->data;
@@ -390,7 +390,7 @@ jbig2_word_stream_buf_get_next_word(Jbig2WordStream *self, int offset, uint32_t
     else if (offset > z->size)
         return -1;
     else {
-        int i;
+        size_t i;
 
         result = 0;
         for (i = 0; i < z->size - offset; i++)
diff --git a/jbig2.h b/jbig2.h
index d5aa52f..624e0ed 100644
--- a/jbig2.h
+++ b/jbig2.h
@@ -56,17 +56,19 @@ typedef struct _Jbig2SymbolDictionary Jbig2SymbolDictionary;
 */
 
 struct _Jbig2Image {
-    int width, height, stride;
+    uint32_t width;
+    uint32_t height;
+    uint32_t stride;
     uint8_t *data;
     int refcount;
 };
 
-Jbig2Image *jbig2_image_new(Jbig2Ctx *ctx, int width, int height);
+Jbig2Image *jbig2_image_new(Jbig2Ctx *ctx, uint32_t width, uint32_t height);
 Jbig2Image *jbig2_image_clone(Jbig2Ctx *ctx, Jbig2Image *image);
 void jbig2_image_release(Jbig2Ctx *ctx, Jbig2Image *image);
 void jbig2_image_free(Jbig2Ctx *ctx, Jbig2Image *image);
 void jbig2_image_clear(Jbig2Ctx *ctx, Jbig2Image *image, int value);
-Jbig2Image *jbig2_image_resize(Jbig2Ctx *ctx, Jbig2Image *image, int width, int height);
+Jbig2Image *jbig2_image_resize(Jbig2Ctx *ctx, Jbig2Image *image, uint32_t width, uint32_t height);
 
 /* errors are returned from the library via a callback. If no callback
    is provided (a NULL argument is passed ot jbig2_ctx_new) a default
diff --git a/jbig2_generic.c b/jbig2_generic.c
index 02fdbfb..9656198 100644
--- a/jbig2_generic.c
+++ b/jbig2_generic.c
@@ -718,7 +718,7 @@ jbig2_immediate_generic_region(Jbig2Ctx *ctx, Jbig2Segment *segment, const byte
     byte seg_flags;
     int8_t gbat[8];
     int offset;
-    int gbat_bytes = 0;
+    uint32_t gbat_bytes = 0;
     Jbig2GenericRegionParams params;
     int code = 0;
     Jbig2Image *image = NULL;
diff --git a/jbig2_halftone.c b/jbig2_halftone.c
index aeab576..acfbc56 100644
--- a/jbig2_halftone.c
+++ b/jbig2_halftone.c
@@ -257,8 +257,8 @@ jbig2_decode_gray_scale_image(Jbig2Ctx *ctx, Jbig2Segment *segment,
 {
     uint8_t **GSVALS = NULL;
     size_t consumed_bytes = 0;
-    int i, j, code, stride;
-    int x, y;
+    uint32_t i, j, stride, x, y;
+    int code;
     Jbig2Image **GSPLANES;
     Jbig2GenericRegionParams rparams;
     Jbig2WordStream *ws = NULL;
@@ -276,9 +276,8 @@ jbig2_decode_gray_scale_image(Jbig2Ctx *ctx, Jbig2Segment *segment,
         if (GSPLANES[i] == NULL) {
             jbig2_error(ctx, JBIG2_SEVERITY_FATAL, segment->number, "failed to allocate %dx%d image for GSPLANES", GSW, GSH);
             /* free already allocated */
-            for (j = i - 1; j >= 0; --j) {
-                jbig2_image_release(ctx, GSPLANES[j]);
-            }
+            for (j = i; j > 0;)
+                jbig2_image_release(ctx, GSPLANES[--j]);
             jbig2_free(ctx->allocator, GSPLANES);
             return NULL;
         }
@@ -323,9 +322,10 @@ jbig2_decode_gray_scale_image(Jbig2Ctx *ctx, Jbig2Segment *segment,
     }
 
     /* C.5 step 2. Set j = GSBPP-2 */
-    j = GSBPP - 2;
+    j = GSBPP - 1;
     /* C.5 step 3. decode loop */
-    while (j >= 0) {
+    while (j > 0) {
+        j--;
         /*  C.5 step 3. (a) */
         if (GSMMR) {
             code = jbig2_decode_halftone_mmr(ctx, &rparams, data + consumed_bytes, size - consumed_bytes, GSPLANES[j], &consumed_bytes);
@@ -345,7 +345,6 @@ jbig2_decode_gray_scale_image(Jbig2Ctx *ctx, Jbig2Segment *segment,
             GSPLANES[j]->data[i] ^= GSPLANES[j + 1]->data[i];
 
         /*  C.5 step 3. (c) */
-        --j;
     }
 
     /* allocate GSVALS */
@@ -359,9 +358,8 @@ jbig2_decode_gray_scale_image(Jbig2Ctx *ctx, Jbig2Segment *segment,
         if (GSVALS[i] == NULL) {
             jbig2_error(ctx, JBIG2_SEVERITY_FATAL, segment->number, "failed to allocate GSVALS: %d bytes", GSH * GSW);
             /* free already allocated */
-            for (j = i - 1; j >= 0; --j) {
-                jbig2_free(ctx->allocator, GSVALS[j]);
-            }
+            for (j = i; j > 0;)
+                jbig2_free(ctx->allocator, GSVALS[--j]);
             jbig2_free(ctx->allocator, GSVALS);
             GSVALS = NULL;
             goto cleanup;
@@ -450,7 +448,7 @@ jbig2_decode_halftone_region(Jbig2Ctx *ctx, Jbig2Segment *segment,
     uint8_t **GI;
     Jbig2Image *HSKIP = NULL;
     Jbig2PatternDict *HPATS;
-    int i;
+    uint32_t i;
     uint32_t mg, ng;
     int32_t x, y;
     uint8_t gray_val;
@@ -476,7 +474,7 @@ jbig2_decode_halftone_region(Jbig2Ctx *ctx, Jbig2Segment *segment,
 
     /* calculate ceil(log2(HNUMPATS)) */
     HBPP = 0;
-    while (HNUMPATS > (1 << ++HBPP));
+    while (HNUMPATS > (1U << ++HBPP));
 
     /* 6.6.5 point 4. decode gray-scale image as mentioned in annex C */
     GI = jbig2_decode_gray_scale_image(ctx, segment, data, size,
diff --git a/jbig2_huffman.c b/jbig2_huffman.c
index 4521b48..f77981b 100644
--- a/jbig2_huffman.c
+++ b/jbig2_huffman.c
@@ -47,16 +47,16 @@ struct _Jbig2HuffmanState {
        is (offset + 4) * 8. */
     uint32_t this_word;
     uint32_t next_word;
-    int offset_bits;
-    int offset;
-    int offset_limit;
+    uint32_t offset_bits;
+    uint32_t offset;
+    uint32_t offset_limit;
 
     Jbig2WordStream *ws;
     Jbig2Ctx *ctx;
 };
 
 static uint32_t
-huff_get_next_word(Jbig2HuffmanState *hs, int offset)
+huff_get_next_word(Jbig2HuffmanState *hs, uint32_t offset)
 {
     uint32_t word = 0;
     Jbig2WordStream *ws = hs->ws;
@@ -213,7 +213,7 @@ jbig2_huffman_advance(Jbig2HuffmanState *hs, int offset)
 /* return the offset of the huffman decode pointer (in bytes)
  * from the beginning of the WordStream
  */
-int
+uint32_t
 jbig2_huffman_offset(Jbig2HuffmanState *hs)
 {
     return hs->offset + (hs->offset_bits >> 3);
diff --git a/jbig2_huffman.h b/jbig2_huffman.h
index 5d1e6e0..cfda9e0 100644
--- a/jbig2_huffman.h
+++ b/jbig2_huffman.h
@@ -64,7 +64,7 @@ void jbig2_huffman_skip(Jbig2HuffmanState *hs);
 
 void jbig2_huffman_advance(Jbig2HuffmanState *hs, int offset);
 
-int jbig2_huffman_offset(Jbig2HuffmanState *hs);
+uint32_t jbig2_huffman_offset(Jbig2HuffmanState *hs);
 
 int32_t jbig2_huffman_get(Jbig2HuffmanState *hs, const Jbig2HuffmanTable *table, bool *oob);
 
diff --git a/jbig2_image.c b/jbig2_image.c
index 1ae614e..94e5a4c 100644
--- a/jbig2_image.c
+++ b/jbig2_image.c
@@ -32,10 +32,10 @@
 
 /* allocate a Jbig2Image structure and its associated bitmap */
 Jbig2Image *
-jbig2_image_new(Jbig2Ctx *ctx, int width, int height)
+jbig2_image_new(Jbig2Ctx *ctx, uint32_t width, uint32_t height)
 {
     Jbig2Image *image;
-    int stride;
+    uint32_t stride;
     int64_t check;
 
     image = jbig2_new(ctx, Jbig2Image, 1);
@@ -99,7 +99,7 @@ jbig2_image_free(Jbig2Ctx *ctx, Jbig2Image *image)
 
 /* resize a Jbig2Image */
 Jbig2Image *
-jbig2_image_resize(Jbig2Ctx *ctx, Jbig2Image *image, int width, int height)
+jbig2_image_resize(Jbig2Ctx *ctx, Jbig2Image *image, uint32_t width, uint32_t height)
 {
     if (width == image->width) {
         /* check for integer multiplication overflow */
@@ -133,11 +133,11 @@ jbig2_image_resize(Jbig2Ctx *ctx, Jbig2Image *image, int width, int height)
 static int
 jbig2_image_compose_unopt(Jbig2Ctx *ctx, Jbig2Image *dst, Jbig2Image *src, int x, int y, Jbig2ComposeOp op)
 {
-    int i, j;
-    int sw = src->width;
-    int sh = src->height;
-    int sx = 0;
-    int sy = 0;
+    uint32_t i, j;
+    uint32_t sw = src->width;
+    uint32_t sh = src->height;
+    uint32_t sx = 0;
+    uint32_t sy = 0;
 
     /* clip to the dst image boundaries */
     if (x < 0) {
@@ -200,10 +200,10 @@ jbig2_image_compose_unopt(Jbig2Ctx *ctx, Jbig2Image *dst, Jbig2Image *src, int x
 int
 jbig2_image_compose(Jbig2Ctx *ctx, Jbig2Image *dst, Jbig2Image *src, int x, int y, Jbig2ComposeOp op)
 {
-    int i, j;
-    int w, h;
-    int leftbyte, rightbyte;
-    int shift;
+    uint32_t i, j;
+    uint32_t w, h;
+    uint32_t leftbyte, rightbyte;
+    uint32_t shift;
     uint8_t *s, *ss;
     uint8_t *d, *dd;
     uint8_t mask, rightmask;
@@ -226,8 +226,8 @@ jbig2_image_compose(Jbig2Ctx *ctx, Jbig2Image *dst, Jbig2Image *src, int x, int
         h += y;
         y = 0;
     }
-    w = (x + w < dst->width) ? w : dst->width - x;
-    h = (y + h < dst->height) ? h : dst->height - y;
+    w = ((uint32_t)x + w < dst->width) ? w : ((dst->width >= (uint32_t)x) ? dst->width - (uint32_t)x : 0);
+    h = ((uint32_t)y + h < dst->height) ? h : ((dst->height >= (uint32_t)y) ? dst->height - (uint32_t)y : 0);
 #ifdef JBIG2_DEBUG
     jbig2_error(ctx, JBIG2_SEVERITY_DEBUG, -1, "compositing %dx%d at (%d, %d) after clipping\n", w, h, x, y);
 #endif
@@ -249,8 +249,8 @@ jbig2_image_compose(Jbig2Ctx *ctx, Jbig2Image *dst, Jbig2Image *src, int x, int
     }
 #endif
 
-    leftbyte = x >> 3;
-    rightbyte = (x + w - 1) >> 3;
+    leftbyte = (uint32_t)x >> 3;
+    rightbyte = ((uint32_t)x + w - 1) >> 3;
     shift = x & 7;
 
     /* general OR case */
diff --git a/jbig2_mmr.c b/jbig2_mmr.c
index d4cd3a2..390e27c 100644
--- a/jbig2_mmr.c
+++ b/jbig2_mmr.c
@@ -38,19 +38,21 @@
 #include "jbig2_mmr.h"
 
 typedef struct {
-    int width;
-    int height;
+    uint32_t width;
+    uint32_t height;
     const byte *data;
     size_t size;
-    int data_index;
-    int bit_index;
+    uint32_t data_index;
+    uint32_t bit_index;
     uint32_t word;
 } Jbig2MmrCtx;
 
+#define MINUS1 ((uint32_t)-1)
+
 static void
 jbig2_decode_mmr_init(Jbig2MmrCtx *mmr, int width, int height, const byte *data, size_t size)
 {
-    int i;
+    size_t i;
     uint32_t word = 0;
 
     mmr->width = width;
@@ -732,14 +734,14 @@ const mmr_table_node jbig2_mmr_black_decode[] = {
 #define getbit(buf, x) ( ( buf[x >> 3] >> ( 7 - (x & 7) ) ) & 1 )
 
 static int
-jbig2_find_changing_element(const byte *line, int x, int w)
+jbig2_find_changing_element(const byte *line, uint32_t x, uint32_t w)
 {
     int a, b;
 
     if (line == 0)
-        return w;
+        return (int)w;
 
-    if (x == -1) {
+    if (x == MINUS1) {
         a = 0;
         x = 0;
     } else {
@@ -758,7 +760,7 @@ jbig2_find_changing_element(const byte *line, int x, int w)
 }
 
 static int
-jbig2_find_changing_element_of_color(const byte *line, int x, int w, int color)
+jbig2_find_changing_element_of_color(const byte *line, uint32_t x, uint32_t w, int color)
 {
     if (line == 0)
         return w;
@@ -772,9 +774,9 @@ static const byte lm[8] = { 0xFF, 0x7F, 0x3F, 0x1F, 0x0F, 0x07, 0x03, 0x01 };
 static const byte rm[8] = { 0x00, 0x80, 0xC0, 0xE0, 0xF0, 0xF8, 0xFC, 0xFE };
 
 static void
-jbig2_set_bits(byte *line, int x0, int x1)
+jbig2_set_bits(byte *line, uint32_t x0, uint32_t x1)
 {
-    int a0, a1, b0, b1, a;
+    uint32_t a0, a1, b0, b1, a;
 
     a0 = x0 >> 3;
     a1 = x1 >> 3;
@@ -831,8 +833,8 @@ jbig2_decode_get_run(Jbig2MmrCtx *mmr, const mmr_table_node *table, int initial_
 static int
 jbig2_decode_mmr_line(Jbig2MmrCtx *mmr, const byte *ref, byte *dst)
 {
-    int a0 = -1;
-    int a1, a2, b1, b2;
+    uint32_t a0 = MINUS1;
+    uint32_t a1, a2, b1, b2;
     int c = 0;                  /* 0 is white, black is 1 */
 
     while (1) {
@@ -840,7 +842,7 @@ jbig2_decode_mmr_line(Jbig2MmrCtx *mmr, const byte *ref, byte *dst)
 
         /* printf ("%08x\n", word); */
 
-        if (a0 >= mmr->width)
+        if (a0 != MINUS1 && a0 >= mmr->width)
             break;
 
         if ((word >> (32 - 3)) == 1) {
@@ -848,7 +850,7 @@ jbig2_decode_mmr_line(Jbig2MmrCtx *mmr, const byte *ref, byte *dst)
 
             jbig2_decode_mmr_consume(mmr, 3);
 
-            if (a0 == -1)
+            if (a0 == MINUS1)
                 a0 = 0;
 
             if (c == 0) {
@@ -860,7 +862,7 @@ jbig2_decode_mmr_line(Jbig2MmrCtx *mmr, const byte *ref, byte *dst)
                     a1 = mmr->width;
                 if (a2 > mmr->width)
                     a2 = mmr->width;
-                if (a2 < a1 || a1 < 0)
+                if (a1 == MINUS1 || a2 < a1)
                     return -1;
                 jbig2_set_bits(dst, a1, a2);
                 a0 = a2;
@@ -874,7 +876,7 @@ jbig2_decode_mmr_line(Jbig2MmrCtx *mmr, const byte *ref, byte *dst)
                     a1 = mmr->width;
                 if (a2 > mmr->width)
                     a2 = mmr->width;
-                if (a1 < a0 || a0 < 0)
+                if (a0 == MINUS1 || a1 < a0)
                     return -1;
                 jbig2_set_bits(dst, a0, a1);
                 a0 = a2;
@@ -888,7 +890,7 @@ jbig2_decode_mmr_line(Jbig2MmrCtx *mmr, const byte *ref, byte *dst)
             b1 = jbig2_find_changing_element_of_color(ref, a0, mmr->width, !c);
             b2 = jbig2_find_changing_element(ref, b1, mmr->width);
             if (c) {
-                if (b2 < a0 || a0 < 0)
+                if (a0 == MINUS1 || b2 < a0)
                     return -1;
                 jbig2_set_bits(dst, a0, b2);
             }
@@ -900,7 +902,7 @@ jbig2_decode_mmr_line(Jbig2MmrCtx *mmr, const byte *ref, byte *dst)
             jbig2_decode_mmr_consume(mmr, 1);
             b1 = jbig2_find_changing_element_of_color(ref, a0, mmr->width, !c);
             if (c) {
-                if (b1 < a0 || a0 < 0)
+                if (a0 == MINUS1 || b1 < a0)
                     return -1;
                 jbig2_set_bits(dst, a0, b1);
             }
@@ -915,7 +917,7 @@ jbig2_decode_mmr_line(Jbig2MmrCtx *mmr, const byte *ref, byte *dst)
             if (b1 + 1 > mmr->width)
                 break;
             if (c) {
-                if (b1 + 1 < a0 || a0 < 0)
+                if (a0 == MINUS1 || b1 + 1 < a0)
                     return -1;
                 jbig2_set_bits(dst, a0, b1 + 1);
             }
@@ -930,7 +932,7 @@ jbig2_decode_mmr_line(Jbig2MmrCtx *mmr, const byte *ref, byte *dst)
             if (b1 + 2 > mmr->width)
                 break;
             if (c) {
-                if (b1 + 2 < a0 || a0 < 0)
+                if (a0 == MINUS1 || b1 + 2 < a0)
                     return -1;
                 jbig2_set_bits(dst, a0, b1 + 2);
             }
@@ -942,10 +944,10 @@ jbig2_decode_mmr_line(Jbig2MmrCtx *mmr, const byte *ref, byte *dst)
             /* printf ("VR(3)\n"); */
             jbig2_decode_mmr_consume(mmr, 7);
             b1 = jbig2_find_changing_element_of_color(ref, a0, mmr->width, !c);
-            if (b1 + 3 > mmr->width)
+            if (b1 + 3 > (int)mmr->width)
                 break;
             if (c) {
-                if (b1 + 3 < a0 || a0 < 0)
+                if (a0 == MINUS1 || b1 + 3 < a0)
                     return -1;
                 jbig2_set_bits(dst, a0, b1 + 3);
             }
@@ -957,10 +959,10 @@ jbig2_decode_mmr_line(Jbig2MmrCtx *mmr, const byte *ref, byte *dst)
             /* printf ("VL(1)\n"); */
             jbig2_decode_mmr_consume(mmr, 3);
             b1 = jbig2_find_changing_element_of_color(ref, a0, mmr->width, !c);
-            if (b1 - 1 < 0)
+            if (b1 < 1)
                 break;
             if (c) {
-                if (b1 - 1 < a0 || a0 < 0)
+                if (a0 == MINUS1 || b1 - 1 < a0)
                     return -1;
                 jbig2_set_bits(dst, a0, b1 - 1);
             }
@@ -972,7 +974,7 @@ jbig2_decode_mmr_line(Jbig2MmrCtx *mmr, const byte *ref, byte *dst)
             /* printf ("VL(2)\n"); */
             jbig2_decode_mmr_consume(mmr, 6);
             b1 = jbig2_find_changing_element_of_color(ref, a0, mmr->width, !c);
-            if (b1 - 2 < 0)
+            if (b1 < 2)
                 break;
             if (c) {
                 if (b1 - 2 < a0 || a0 < 0)
@@ -987,10 +989,10 @@ jbig2_decode_mmr_line(Jbig2MmrCtx *mmr, const byte *ref, byte *dst)
             /* printf ("VL(3)\n"); */
             jbig2_decode_mmr_consume(mmr, 7);
             b1 = jbig2_find_changing_element_of_color(ref, a0, mmr->width, !c);
-            if (b1 - 3 < 0)
+            if (b1 < 3)
                 break;
             if (c) {
-                if (b1 - 3 < a0 || a0 < 0)
+                if (a0 == MINUS1 || b1 - 3 < a0)
                     return -1;
                 jbig2_set_bits(dst, a0, b1 - 3);
             }
@@ -1009,10 +1011,10 @@ int
 jbig2_decode_generic_mmr(Jbig2Ctx *ctx, Jbig2Segment *segment, const Jbig2GenericRegionParams *params, const byte *data, size_t size, Jbig2Image *image)
 {
     Jbig2MmrCtx mmr;
-    const int rowstride = image->stride;
+    const uint32_t rowstride = image->stride;
     byte *dst = image->data;
     byte *ref = NULL;
-    int y;
+    uint32_t y;
     int code = 0;
 
     jbig2_decode_mmr_init(&mmr, image->width, image->height, data, size);
@@ -1047,10 +1049,10 @@ int
 jbig2_decode_halftone_mmr(Jbig2Ctx *ctx, const Jbig2GenericRegionParams *params, const byte *data, size_t size, Jbig2Image *image, size_t *consumed_bytes)
 {
     Jbig2MmrCtx mmr;
-    const int rowstride = image->stride;
+    const uint32_t rowstride = image->stride;
     byte *dst = image->data;
     byte *ref = NULL;
-    int y;
+    uint32_t y;
     int code = 0;
     const uint32_t EOFB = 0x001001;
 
diff --git a/jbig2_page.c b/jbig2_page.c
index 110ff7c..1ed1c8a 100644
--- a/jbig2_page.c
+++ b/jbig2_page.c
@@ -155,9 +155,9 @@ int
 jbig2_end_of_stripe(Jbig2Ctx *ctx, Jbig2Segment *segment, const uint8_t *segment_data)
 {
     Jbig2Page page = ctx->pages[ctx->current_page];
-    int end_row;
+    uint32_t end_row;
 
-    end_row = jbig2_get_int32(segment_data);
+    end_row = jbig2_get_uint32(segment_data);
     if (end_row < page.end_row) {
         jbig2_error(ctx, JBIG2_SEVERITY_WARNING, segment->number,
                     "end of stripe segment with non-positive end row advance" " (new end row %d vs current end row %d)", end_row, page.end_row);
@@ -248,7 +248,7 @@ jbig2_page_add_result(Jbig2Ctx *ctx, Jbig2Page *page, Jbig2Image *image, int x,
 
     /* grow the page to accomodate a new stripe if necessary */
     if (page->striped) {
-        int new_height = y + image->height + page->end_row;
+        uint32_t new_height = y + image->height + page->end_row;
 
         if (page->image->height < new_height) {
             jbig2_error(ctx, JBIG2_SEVERITY_DEBUG, -1, "growing page buffer to %d rows " "to accomodate new stripe", new_height);
diff --git a/jbig2_priv.h b/jbig2_priv.h
index 42ba496..3d44b42 100644
--- a/jbig2_priv.h
+++ b/jbig2_priv.h
@@ -132,7 +132,7 @@ struct _Jbig2Page {
     uint32_t x_resolution, y_resolution;        /* in pixels per meter */
     uint16_t stripe_size;
     bool striped;
-    int end_row;
+    uint32_t end_row;
     uint8_t flags;
     Jbig2Image *image;
 };
@@ -182,7 +182,7 @@ int jbig2_halftone_region(Jbig2Ctx *ctx, Jbig2Segment *segment, const byte *segm
 typedef struct _Jbig2WordStream Jbig2WordStream;
 
 struct _Jbig2WordStream {
-    int (*get_next_word)(Jbig2WordStream *self, int offset, uint32_t *word);
+    int (*get_next_word)(Jbig2WordStream *self, size_t offset, uint32_t *word);
 };
 
 Jbig2WordStream *jbig2_word_stream_buf_new(Jbig2Ctx *ctx, const byte *data, size_t size);
diff --git a/jbig2_segment.c b/jbig2_segment.c
index 2e0db67..5b63706 100644
--- a/jbig2_segment.c
+++ b/jbig2_segment.c
@@ -39,10 +39,10 @@ jbig2_parse_segment_header(Jbig2Ctx *ctx, uint8_t *buf, size_t buf_size, size_t
     uint8_t rtscarf;
     uint32_t rtscarf_long;
     uint32_t *referred_to_segments;
-    int referred_to_segment_count;
-    int referred_to_segment_size;
-    int pa_size;
-    int offset;
+    uint32_t referred_to_segment_count;
+    uint32_t referred_to_segment_size;
+    uint32_t pa_size;
+    uint32_t offset;
 
     /* minimum possible size of a jbig2 segment header */
     if (buf_size < 11)
@@ -83,7 +83,7 @@ jbig2_parse_segment_header(Jbig2Ctx *ctx, uint8_t *buf, size_t buf_size, size_t
 
     /* 7.2.5 */
     if (referred_to_segment_count) {
-        int i;
+        uint32_t i;
 
         referred_to_segments = jbig2_new(ctx, uint32_t, referred_to_segment_count * referred_to_segment_size);
         if (referred_to_segments == NULL) {
diff --git a/jbig2_symbol_dict.c b/jbig2_symbol_dict.c
index 2c71a4c..11a2252 100644
--- a/jbig2_symbol_dict.c
+++ b/jbig2_symbol_dict.c
@@ -88,40 +88,40 @@ jbig2_dump_symbol_dict(Jbig2Ctx *ctx, Jbig2Segment *segment)
 
 /* return a new empty symbol dict */
 Jbig2SymbolDict *
-jbig2_sd_new(Jbig2Ctx *ctx, int n_symbols)
+jbig2_sd_new(Jbig2Ctx *ctx, uint32_t n_symbols)
 {
-    Jbig2SymbolDict *new = NULL;
+    Jbig2SymbolDict *new_dict = NULL;
 
     if (n_symbols < 0) {
         jbig2_error(ctx, JBIG2_SEVERITY_FATAL, -1, "Negative number of symbols in symbol dict: %d", n_symbols);
         return NULL;
     }
 
-    new = jbig2_new(ctx, Jbig2SymbolDict, 1);
-    if (new != NULL) {
-        new->glyphs = jbig2_new(ctx, Jbig2Image *, n_symbols);
-        new->n_symbols = n_symbols;
+    new_dict = jbig2_new(ctx, Jbig2SymbolDict, 1);
+    if (new_dict != NULL) {
+        new_dict->glyphs = jbig2_new(ctx, Jbig2Image *, n_symbols);
+        new_dict->n_symbols = n_symbols;
     } else {
         jbig2_error(ctx, JBIG2_SEVERITY_FATAL, -1, "unable to allocate new empty symbol dict");
         return NULL;
     }
 
-    if (new->glyphs != NULL) {
-        memset(new->glyphs, 0, n_symbols * sizeof(Jbig2Image *));
+    if (new_dict->glyphs != NULL) {
+        memset(new_dict->glyphs, 0, n_symbols * sizeof(Jbig2Image *));
     } else {
         jbig2_error(ctx, JBIG2_SEVERITY_FATAL, -1, "unable to allocate glyphs for new empty symbol dict");
-        jbig2_free(ctx->allocator, new);
+        jbig2_free(ctx->allocator, new_dict);
         return NULL;
     }
 
-    return new;
+    return new_dict;
 }
 
 /* release the memory associated with a symbol dict */
 void
 jbig2_sd_release(Jbig2Ctx *ctx, Jbig2SymbolDict *dict)
 {
-    int i;
+    uint32_t i;
 
     if (dict == NULL)
         return;
@@ -142,12 +142,12 @@ jbig2_sd_glyph(Jbig2SymbolDict *dict, unsigned int id)
 }
 
 /* count the number of dictionary segments referred to by the given segment */
-int
+uint32_t
 jbig2_sd_count_referred(Jbig2Ctx *ctx, Jbig2Segment *segment)
 {
     int index;
     Jbig2Segment *rsegment;
-    int n_dicts = 0;
+    uint32_t n_dicts = 0;
 
     for (index = 0; index < segment->referred_to_segment_count; index++) {
         rsegment = jbig2_find_segment(ctx, segment->referred_to_segments[index]);
@@ -166,8 +166,8 @@ jbig2_sd_list_referred(Jbig2Ctx *ctx, Jbig2Segment *segment)
     int index;
     Jbig2Segment *rsegment;
     Jbig2SymbolDict **dicts;
-    int n_dicts = jbig2_sd_count_referred(ctx, segment);
-    int dindex = 0;
+    uint32_t n_dicts = jbig2_sd_count_referred(ctx, segment);
+    uint32_t dindex = 0;
 
     dicts = jbig2_new(ctx, Jbig2SymbolDict *, n_dicts);
     if (dicts == NULL) {
@@ -195,10 +195,10 @@ jbig2_sd_list_referred(Jbig2Ctx *ctx, Jbig2Segment *segment)
 /* generate a new symbol dictionary by concatenating a list of
    existing dictionaries */
 Jbig2SymbolDict *
-jbig2_sd_cat(Jbig2Ctx *ctx, int n_dicts, Jbig2SymbolDict **dicts)
+jbig2_sd_cat(Jbig2Ctx *ctx, uint32_t n_dicts, Jbig2SymbolDict **dicts)
 {
-    int i, j, k, symbols;
-    Jbig2SymbolDict *new = NULL;
+    uint32_t i, j, k, symbols;
+    Jbig2SymbolDict *new_dict = NULL;
 
     /* count the imported symbols and allocate a new array */
     symbols = 0;
@@ -206,17 +206,17 @@ jbig2_sd_cat(Jbig2Ctx *ctx, int n_dicts, Jbig2SymbolDict **dicts)
         symbols += dicts[i]->n_symbols;
 
     /* fill a new array with cloned glyph pointers */
-    new = jbig2_sd_new(ctx, symbols);
-    if (new != NULL) {
+    new_dict = jbig2_sd_new(ctx, symbols);
+    if (new_dict != NULL) {
         k = 0;
         for (i = 0; i < n_dicts; i++)
             for (j = 0; j < dicts[i]->n_symbols; j++)
-                new->glyphs[k++] = jbig2_image_clone(ctx, dicts[i]->glyphs[j]);
+                new_dict->glyphs[k++] = jbig2_image_clone(ctx, dicts[i]->glyphs[j]);
     } else {
         jbig2_error(ctx, JBIG2_SEVERITY_WARNING, -1, "failed to allocate new symbol dictionary");
     }
 
-    return new;
+    return new_dict;
 }
 
 /* Decoding routines */
@@ -431,7 +431,7 @@ jbig2_decode_symbol_dict(Jbig2Ctx *ctx,
 
                     if (REFAGGNINST > 1) {
                         Jbig2Image *image;
-                        int i;
+                        uint32_t i;
 
                         if (tparams == NULL) {
                             /* First time through, we need to initialise the */
@@ -512,7 +512,7 @@ jbig2_decode_symbol_dict(Jbig2Ctx *ctx,
                         uint32_t ID;
                         int32_t RDX, RDY;
                         int BMSIZE = 0;
-                        int ninsyms = params->SDNUMINSYMS;
+                        uint32_t ninsyms = params->SDNUMINSYMS;
                         int code1 = 0;
                         int code2 = 0;
                         int code3 = 0;
@@ -609,8 +609,9 @@ jbig2_decode_symbol_dict(Jbig2Ctx *ctx,
         if (params->SDHUFF && !params->SDREFAGG) {
             /* 6.5.9 */
             Jbig2Image *image;
-            int BMSIZE = jbig2_huffman_get(hs, params->SDHUFFBMSIZE, &code);
-            int j, x;
+            uint32_t BMSIZE = jbig2_huffman_get(hs, params->SDHUFFBMSIZE, &code);
+            uint32_t j;
+            int x;
 
             if (code || (BMSIZE < 0)) {
                 jbig2_error(ctx, JBIG2_SEVERITY_FATAL, segment->number, "error decoding size of collective bitmap!");
@@ -700,22 +701,22 @@ jbig2_decode_symbol_dict(Jbig2Ctx *ctx,
         jbig2_error(ctx, JBIG2_SEVERITY_FATAL, segment->number, "failed to allocate symbols exported from symbols dictionary");
         goto cleanup4;
     } else {
-        int i = 0;
-        int j = 0;
-        int k;
+        uint32_t i = 0;
+        uint32_t j = 0;
+        uint32_t k;
         int exflag = 0;
-        int64_t limit = params->SDNUMINSYMS + params->SDNUMNEWSYMS;
-        int32_t exrunlength;
+        uint32_t limit = params->SDNUMINSYMS + params->SDNUMNEWSYMS;
+        uint32_t exrunlength;
         int zerolength = 0;
 
         while (i < limit) {
             if (params->SDHUFF)
                 exrunlength = jbig2_huffman_get(hs, SBHUFFRSIZE, &code);
             else
-                code = jbig2_arith_int_decode(IAEX, as, &exrunlength);
+                code = jbig2_arith_int_decode(IAEX, as, (int32_t *)&exrunlength);
             /* prevent infinite loop */
             zerolength = exrunlength > 0 ? 0 : zerolength + 1;
-            if (code || (exrunlength > limit - i) || (exrunlength < 0) || (zerolength > 4) || (exflag && (exrunlength > params->SDNUMEXSYMS - j))) {
+            if (code || (exrunlength > limit - i) || (exrunlength < 0) || (zerolength > 4) || (exflag && (exrunlength + j > params->SDNUMEXSYMS))) {
                 if (code)
                     jbig2_error(ctx, JBIG2_SEVERITY_FATAL, segment->number, "failed to decode exrunlength for exported symbols");
                 else if (exrunlength <= 0)
@@ -797,8 +798,8 @@ jbig2_symbol_dictionary(Jbig2Ctx *ctx, Jbig2Segment *segment, const byte *segmen
 {
     Jbig2SymbolDictParams params;
     uint16_t flags;
-    int sdat_bytes;
-    int offset;
+    uint32_t sdat_bytes;
+    uint32_t offset;
     Jbig2ArithCx *GB_stats = NULL;
     Jbig2ArithCx *GR_stats = NULL;
     int table_index = 0;
@@ -951,7 +952,7 @@ jbig2_symbol_dictionary(Jbig2Ctx *ctx, Jbig2Segment *segment, const byte *segmen
 
     /* 7.4.2.2 (2) */
     {
-        int n_dicts = jbig2_sd_count_referred(ctx, segment);
+        uint32_t n_dicts = jbig2_sd_count_referred(ctx, segment);
         Jbig2SymbolDict **dicts = NULL;
 
         if (n_dicts > 0) {
diff --git a/jbig2_symbol_dict.h b/jbig2_symbol_dict.h
index d56d62d..30211d4 100644
--- a/jbig2_symbol_dict.h
+++ b/jbig2_symbol_dict.h
@@ -32,18 +32,18 @@ int jbig2_symbol_dictionary(Jbig2Ctx *ctx, Jbig2Segment *segment, const byte *se
 Jbig2Image *jbig2_sd_glyph(Jbig2SymbolDict *dict, unsigned int id);
 
 /* return a new empty symbol dict */
-Jbig2SymbolDict *jbig2_sd_new(Jbig2Ctx *ctx, int n_symbols);
+Jbig2SymbolDict *jbig2_sd_new(Jbig2Ctx *ctx, uint32_t n_symbols);
 
 /* release the memory associated with a symbol dict */
 void jbig2_sd_release(Jbig2Ctx *ctx, Jbig2SymbolDict *dict);
 
 /* generate a new symbol dictionary by concatenating a list of
    existing dictionaries */
-Jbig2SymbolDict *jbig2_sd_cat(Jbig2Ctx *ctx, int n_dicts, Jbig2SymbolDict **dicts);
+Jbig2SymbolDict *jbig2_sd_cat(Jbig2Ctx *ctx, uint32_t n_dicts, Jbig2SymbolDict **dicts);
 
 /* count the number of dictionary segments referred
    to by the given segment */
-int jbig2_sd_count_referred(Jbig2Ctx *ctx, Jbig2Segment *segment);
+uint32_t jbig2_sd_count_referred(Jbig2Ctx *ctx, Jbig2Segment *segment);
 
 /* return an array of pointers to symbol dictionaries referred
    to by a segment */
diff --git a/jbig2_text.c b/jbig2_text.c
index 5c99640..e77460f 100644
--- a/jbig2_text.c
+++ b/jbig2_text.c
@@ -55,7 +55,7 @@
 int
 jbig2_decode_text_region(Jbig2Ctx *ctx, Jbig2Segment *segment,
                          const Jbig2TextRegionParams *params,
-                         const Jbig2SymbolDict *const *dicts, const int n_dicts,
+                         const Jbig2SymbolDict *const *dicts, const uint32_t n_dicts,
                          Jbig2Image *image, const byte *data, const size_t size, Jbig2ArithCx *GR_stats, Jbig2ArithState *as, Jbig2WordStream *ws)
 {
     /* relevent bits of 6.4.4 */
@@ -476,19 +476,19 @@ cleanup2:
 int
 jbig2_text_region(Jbig2Ctx *ctx, Jbig2Segment *segment, const byte *segment_data)
 {
-    int offset = 0;
+    uint32_t offset = 0;
     Jbig2RegionSegmentInfo region_info;
     Jbig2TextRegionParams params;
     Jbig2Image *image = NULL;
     Jbig2SymbolDict **dicts = NULL;
-    int n_dicts = 0;
+    uint32_t n_dicts = 0;
     uint16_t flags = 0;
     uint16_t huffman_flags = 0;
     Jbig2ArithCx *GR_stats = NULL;
     int code = 0;
     Jbig2WordStream *ws = NULL;
     Jbig2ArithState *as = NULL;
-    int table_index = 0;
+    uint32_t table_index = 0;
     const Jbig2HuffmanParams *huffman_params = NULL;
 
     /* 7.4.1 */
@@ -779,7 +779,7 @@ jbig2_text_region(Jbig2Ctx *ctx, Jbig2Segment *segment, const byte *segment_data
         code = jbig2_error(ctx, JBIG2_SEVERITY_FATAL, segment->number, "unable to retrive symbol dictionaries! previous parsing error?");
         goto cleanup1;
     } else {
-        int index;
+        uint32_t index;
 
         if (dicts[0] == NULL) {
             code = jbig2_error(ctx, JBIG2_SEVERITY_WARNING, segment->number, "unable to find first referenced symbol dictionary!");
@@ -823,8 +823,8 @@ jbig2_text_region(Jbig2Ctx *ctx, Jbig2Segment *segment, const byte *segment_data
     }
 
     if (!params.SBHUFF) {
-        int SBSYMCODELEN, index;
-        int SBNUMSYMS = 0;
+        uint32_t SBSYMCODELEN, index;
+        uint32_t SBNUMSYMS = 0;
 
         for (index = 0; index < n_dicts; index++) {
             SBNUMSYMS += dicts[index]->n_symbols;
@@ -840,7 +840,7 @@ jbig2_text_region(Jbig2Ctx *ctx, Jbig2Segment *segment, const byte *segment_data
         }
 
         /* Table 31 */
-        for (SBSYMCODELEN = 0; (1 << SBSYMCODELEN) < SBNUMSYMS; SBSYMCODELEN++) {
+        for (SBSYMCODELEN = 0; (1U << SBSYMCODELEN) < SBNUMSYMS; SBSYMCODELEN++) {
         }
         params.IAID = jbig2_arith_iaid_ctx_new(ctx, SBSYMCODELEN);
         params.IARI = jbig2_arith_int_ctx_new(ctx);
diff --git a/jbig2_text.h b/jbig2_text.h
index aec2732..51d242e 100644
--- a/jbig2_text.h
+++ b/jbig2_text.h
@@ -70,5 +70,5 @@ typedef struct {
 int
 jbig2_decode_text_region(Jbig2Ctx *ctx, Jbig2Segment *segment,
                          const Jbig2TextRegionParams *params,
-                         const Jbig2SymbolDict *const *dicts, const int n_dicts,
+                         const Jbig2SymbolDict *const *dicts, const uint32_t n_dicts,
                          Jbig2Image *image, const byte *data, const size_t size, Jbig2ArithCx *GR_stats, Jbig2ArithState *as, Jbig2WordStream *ws);
-- 
2.9.1

