7 files changed, 27 insertions, 19 deletions
diff --git a/xdiff/xdiff.h b/xdiff/xdiff.h
index bb56b23f34..2cecde5afe 100644
--- a/xdiff/xdiff.h
+++ b/xdiff/xdiff.h
@@ -85,7 +85,7 @@ typedef struct s_xpparam {
 	regex_t **ignore_regex;
 	size_t ignore_regex_nr;
 
-	/* See Documentation/diff-options.txt. */
+	/* See Documentation/diff-options.adoc. */
 	char **anchors;
 	size_t anchors_nr;
 } xpparam_t;
diff --git a/xdiff/xdiffi.c b/xdiff/xdiffi.c
index 4685ba6137..5a96e36dfb 100644
--- a/xdiff/xdiffi.c
+++ b/xdiff/xdiffi.c
@@ -19,7 +19,6 @@
  *  Davide Libenzi <davidel@xmailserver.org>
  *
  */
-#define DISABLE_SIGN_COMPARE_WARNINGS
 
 #include "xinclude.h"
 
@@ -212,8 +211,10 @@ static long xdl_split(unsigned long const *ha1, long off1, long lim1,
 			for (d = fmax; d >= fmin; d -= 2) {
 				i1 = XDL_MIN(kvdf[d], lim1);
 				i2 = i1 - d;
-				if (lim2 < i2)
-					i1 = lim2 + d, i2 = lim2;
+				if (lim2 < i2) {
+					i1 = lim2 + d;
+					i2 = lim2;
+				}
 				if (fbest < i1 + i2) {
 					fbest = i1 + i2;
 					fbest1 = i1;
@@ -224,8 +225,10 @@ static long xdl_split(unsigned long const *ha1, long off1, long lim1,
 			for (d = bmax; d >= bmin; d -= 2) {
 				i1 = XDL_MAX(off1, kvdb[d]);
 				i2 = i1 - d;
-				if (i2 < off2)
-					i1 = off2 + d, i2 = off2;
+				if (i2 < off2) {
+					i1 = off2 + d;
+					i2 = off2;
+				}
 				if (i1 + i2 < bbest) {
 					bbest = i1 + i2;
 					bbest1 = i1;
@@ -1014,7 +1017,7 @@ static void xdl_mark_ignorable_lines(xdchange_t *xscr, xdfenv_t *xe, long flags)
 
 static int record_matches_regex(xrecord_t *rec, xpparam_t const *xpp) {
 	regmatch_t regmatch;
-	int i;
+	size_t i;
 
 	for (i = 0; i < xpp->ignore_regex_nr; i++)
 		if (!regexec_buf(xpp->ignore_regex[i], rec->ptr, rec->size, 1,
diff --git a/xdiff/xemit.c b/xdiff/xemit.c
index 75f0fe4986..1d40c9cb40 100644
--- a/xdiff/xemit.c
+++ b/xdiff/xemit.c
@@ -43,6 +43,10 @@ static int xdl_emit_record(xdfile_t *xdf, long ri, char const *pre, xdemitcb_t *
 	return 0;
 }
 
+static long saturating_add(long a, long b)
+{
+	return signed_add_overflows(a, b) ? LONG_MAX : a + b;
+}
 
 /*
  * Starting at the passed change atom, find the latest change atom to be included
@@ -52,9 +56,11 @@ static int xdl_emit_record(xdfile_t *xdf, long ri, char const *pre, xdemitcb_t *
 xdchange_t *xdl_get_hunk(xdchange_t **xscr, xdemitconf_t const *xecfg)
 {
 	xdchange_t *xch, *xchp, *lxch;
-	long max_common = 2 * xecfg->ctxlen + xecfg->interhunkctxlen;
+	long max_common = saturating_add(saturating_add(xecfg->ctxlen,
+							xecfg->ctxlen),
+					 xecfg->interhunkctxlen);
 	long max_ignorable = xecfg->ctxlen;
-	unsigned long ignored = 0; /* number of ignored blank lines */
+	long ignored = 0; /* number of ignored blank lines */
 
 	/* remove ignorable changes that are too far before other changes */
 	for (xchp = *xscr; xchp && xchp->ignore; xchp = xchp->next) {
diff --git a/xdiff/xhistogram.c b/xdiff/xhistogram.c
index 16a8fe2f3f..040d81e0bc 100644
--- a/xdiff/xhistogram.c
+++ b/xdiff/xhistogram.c
@@ -106,7 +106,7 @@ static int scanA(struct histindex *index, int line1, int count1)
 	unsigned int chain_len;
 	struct record **rec_chain, *rec;
 
-	for (ptr = LINE_END(1); line1 <= ptr; ptr--) {
+	for (ptr = LINE_END(1); (unsigned int)line1 <= ptr; ptr--) {
 		tbl_idx = TABLE_HASH(index, 1, ptr);
 		rec_chain = index->records + tbl_idx;
 		rec = *rec_chain;
@@ -181,14 +181,14 @@ static int try_lcs(struct histindex *index, struct region *lcs, int b_ptr,
 			be = bs;
 			rc = rec->cnt;
 
-			while (line1 < as && line2 < bs
+			while ((unsigned int)line1 < as && (unsigned int)line2 < bs
 				&& CMP(index, 1, as - 1, 2, bs - 1)) {
 				as--;
 				bs--;
 				if (1 < rc)
 					rc = XDL_MIN(rc, CNT(index, as));
 			}
-			while (ae < LINE_END(1) && be < LINE_END(2)
+			while (ae < (unsigned int)LINE_END(1) && be < (unsigned int)LINE_END(2)
 				&& CMP(index, 1, ae + 1, 2, be + 1)) {
 				ae++;
 				be++;
@@ -313,7 +313,7 @@ redo:
 	if (count1 <= 0 && count2 <= 0)
 		return 0;
 
-	if (LINE_END(1) >= MAX_PTR)
+	if ((unsigned int)LINE_END(1) >= MAX_PTR)
 		return -1;
 
 	if (!count1) {
diff --git a/xdiff/xinclude.h b/xdiff/xinclude.h
index 7e56542526..a4285ac0eb 100644
--- a/xdiff/xinclude.h
+++ b/xdiff/xinclude.h
@@ -23,8 +23,6 @@
 #if !defined(XINCLUDE_H)
 #define XINCLUDE_H
 
-#define DISABLE_SIGN_COMPARE_WARNINGS
-
 #include "git-compat-util.h"
 #include "xmacros.h"
 #include "xdiff.h"
diff --git a/xdiff/xpatience.c b/xdiff/xpatience.c
index a2d8955537..77dc411d19 100644
--- a/xdiff/xpatience.c
+++ b/xdiff/xpatience.c
@@ -19,6 +19,7 @@
  *  Davide Libenzi <davidel@xmailserver.org>
  *
  */
+
 #include "xinclude.h"
 
 /*
@@ -63,7 +64,7 @@ struct hashmap {
 
 		/*
 		 * If 1, this entry can serve as an anchor. See
-		 * Documentation/diff-options.txt for more information.
+		 * Documentation/diff-options.adoc for more information.
 		 */
 		unsigned anchor : 1;
 	} *entries, *first, *last;
@@ -75,7 +76,7 @@ struct hashmap {
 
 static int is_anchor(xpparam_t const *xpp, const char *line)
 {
-	int i;
+	size_t i;
 	for (i = 0; i < xpp->anchors_nr; i++) {
 		if (!strncmp(line, xpp->anchors[i], strlen(xpp->anchors[i])))
 			return 1;
diff --git a/xdiff/xutils.c b/xdiff/xutils.c
index 9e36f24875..444a108f87 100644
--- a/xdiff/xutils.c
+++ b/xdiff/xutils.c
@@ -375,7 +375,7 @@ static int xdl_format_hunk_hdr(long s1, long c1, long s2, long c2,
 	nb += 3;
 	if (func && funclen) {
 		buf[nb++] = ' ';
-		if (funclen > sizeof(buf) - nb - 1)
+		if ((size_t)funclen > sizeof(buf) - nb - 1)
 			funclen = sizeof(buf) - nb - 1;
 		memcpy(buf + nb, func, funclen);
 		nb += funclen;
@@ -437,7 +437,7 @@ void* xdl_alloc_grow_helper(void *p, long nr, long *alloc, size_t size)
 {
 	void *tmp = NULL;
 	size_t n = ((LONG_MAX - 16) / 2 >= *alloc) ? 2 * *alloc + 16 : LONG_MAX;
-	if (nr > n)
+	if ((size_t)nr > n)
 		n = nr;
 	if (SIZE_MAX / size >= n)
 		tmp = xdl_realloc(p, n * size);