diff --git a/Documentation/technical/api-diff.txt b/Documentation/technical/api-diff.txt
index 20b0241d30..2d2ebc04b7 100644
--- a/Documentation/technical/api-diff.txt
+++ b/Documentation/technical/api-diff.txt
@@ -32,7 +32,7 @@ Calling sequence
 
 * As you find different pairs of files, call `diff_change()` to feed
   modified files, `diff_addremove()` to feed created or deleted files,
-  or `diff_unmerged()` to feed a file whose state is 'unmerged' to the
+  or `diff_unmerge()` to feed a file whose state is 'unmerged' to the
   API.  These are thin wrappers to a lower-level `diff_queue()` function
   that is flexible enough to record any of these kinds of changes.
 
@@ -50,7 +50,7 @@ Data structures
 This is the internal representation for a single file (blob).  It
 records the blob object name (if known -- for a work tree file it
 typically is a NUL SHA-1), filemode and pathname.  This is what the
-`diff_addremove()`, `diff_change()` and `diff_unmerged()` synthesize and
+`diff_addremove()`, `diff_change()` and `diff_unmerge()` synthesize and
 feed `diff_queue()` function with.
 
 * `struct diff_filepair`
diff --git a/fsck.c b/fsck.c
index 6f266c1ea4..60bd4bbf6a 100644
--- a/fsck.c
+++ b/fsck.c
@@ -349,7 +349,7 @@ int fsck_error_function(struct object *obj, int type, const char *fmt, ...)
 	va_list ap;
 	struct strbuf sb = STRBUF_INIT;
 
-	strbuf_addf(&sb, "object %s:", obj->sha1?sha1_to_hex(obj->sha1):"(null)");
+	strbuf_addf(&sb, "object %s:", sha1_to_hex(obj->sha1));
 
 	va_start(ap, fmt);
 	strbuf_vaddf(&sb, fmt, ap);
diff --git a/git-submodule.sh b/git-submodule.sh
index c1d3a5e2fa..c571d320d0 100755
--- a/git-submodule.sh
+++ b/git-submodule.sh
@@ -499,7 +499,7 @@ Maybe you want to use 'update --init'?")"
 				# Run fetch only if $sha1 isn't present or it
 				# is not reachable from a ref.
 				(clear_local_git_env; cd "$path" &&
-					((rev=$(git rev-list -n 1 $sha1 --not --all 2>/dev/null) &&
+					( (rev=$(git rev-list -n 1 $sha1 --not --all 2>/dev/null) &&
 					 test -z "$rev") || git-fetch)) ||
 				die "$(eval_gettext "Unable to fetch in submodule path '\$path'")"
 			fi
diff --git a/rerere.c b/rerere.c
index e3407cf334..dcb525a4d0 100644
--- a/rerere.c
+++ b/rerere.c
@@ -47,8 +47,14 @@ static void read_rr(struct string_list *rr)
 		name = xstrdup(buf);
 		if (fgetc(in) != '\t')
 			die("corrupt MERGE_RR");
-		for (i = 0; i < sizeof(buf) && (buf[i] = fgetc(in)); i++)
-			; /* do nothing */
+		for (i = 0; i < sizeof(buf); i++) {
+			int c = fgetc(in);
+			if (c < 0)
+				die("corrupt MERGE_RR");
+			buf[i] = c;
+			if (c == 0)
+				 break;
+		}
 		if (i == sizeof(buf))
 			die("filename too long");
 		string_list_insert(rr, buf)->util = name;
diff --git a/setup.c b/setup.c
index 013ad11275..ce87900ce3 100644
--- a/setup.c
+++ b/setup.c
@@ -382,7 +382,7 @@ const char *read_gitfile_gently(const char *path)
 	const char *slash;
 	struct stat st;
 	int fd;
-	size_t len;
+	ssize_t len;
 
 	if (stat(path, &st))
 		return NULL;
diff --git a/t/t7810-grep.sh b/t/t7810-grep.sh
index e061108a64..69bd576d1c 100755
--- a/t/t7810-grep.sh
+++ b/t/t7810-grep.sh
@@ -33,9 +33,9 @@ test_expect_success setup '
 		echo HeLLo_world
 	} >hello_world &&
 	{
-		echo aab
-		echo a+b
-		echo a\\+b
+		echo "a+b*c"
+		echo "a+bc"
+		echo "abc"
 	} >ab &&
 	echo vvv >v &&
 	echo ww w >w &&
@@ -233,14 +233,14 @@ do
 		test_cmp expected actual
 	'
 	test_expect_success "grep $L with grep.extendedRegexp=false" '
-		echo "ab:a+b" >expected &&
-		git -c grep.extendedRegexp=false grep "a+b" >actual &&
+		echo "ab:a+bc" >expected &&
+		git -c grep.extendedRegexp=false grep "a+b*c" ab >actual &&
 		test_cmp expected actual
 	'
 
 	test_expect_success "grep $L with grep.extendedRegexp=true" '
-		echo "ab:aab" >expected &&
-		git -c grep.extendedRegexp=true grep "a+b" >actual &&
+		echo "ab:abc" >expected &&
+		git -c grep.extendedRegexp=true grep "a+b*c" ab >actual &&
 		test_cmp expected actual
 	'
 done
@@ -636,7 +636,7 @@ test_expect_success LIBPCRE 'grep -P pattern' '
 '
 
 test_expect_success 'grep pattern with grep.extendedRegexp=true' '
-	:>empty &&
+	>empty &&
 	test_must_fail git -c grep.extendedregexp=true \
 		grep "\p{Ps}.*?\p{Pe}" hello.c >actual &&
 	test_cmp empty actual
@@ -650,10 +650,10 @@ test_expect_success LIBPCRE 'grep -P pattern with grep.extendedRegexp=true' '
 
 test_expect_success LIBPCRE 'grep -P -v pattern' '
 	{
-		echo ab:a+b
-		echo ab:a\\+b
+		echo "ab:a+b*c"
+		echo "ab:a+bc"
 	} >expected &&
-	git grep -P -v "aab" ab >actual &&
+	git grep -P -v "abc" ab >actual &&
 	test_cmp expected actual
 '
 
@@ -686,39 +686,33 @@ test_expect_success LIBPCRE 'grep -P invalidpattern properly dies ' '
 	test_must_fail git grep -P "a["
 '
 
-test_expect_success 'grep -F -E -G pattern' '
-	echo ab:a+b >expected &&
-	git grep -F -E -G a+b >actual &&
-	test_cmp expected actual
-'
-
-test_expect_success 'grep -F -G -E pattern' '
-	echo ab:aab >expected &&
-	git grep -F -G -E a+b >actual &&
+test_expect_success 'grep -G -E -F pattern' '
+	echo "ab:a+b*c" >expected &&
+	git grep -G -E -F "a+b*c" ab >actual &&
 	test_cmp expected actual
 '
 
 test_expect_success 'grep -E -F -G pattern' '
-	echo ab:aab >expected &&
-	git grep -E -F -G a\\+b >actual &&
+	echo "ab:a+bc" >expected &&
+	git grep -E -F -G "a+b*c" ab >actual &&
 	test_cmp expected actual
 '
 
-test_expect_success 'grep -E -G -F pattern' '
-	echo ab:a\\+b >expected &&
-	git grep -E -G -F a\\+b >actual &&
+test_expect_success 'grep -F -G -E pattern' '
+	echo "ab:abc" >expected &&
+	git grep -F -G -E "a+b*c" ab >actual &&
 	test_cmp expected actual
 '
 
-test_expect_success 'grep -G -F -E pattern' '
-	echo ab:a+b >expected &&
-	git grep -G -F -E a\\+b >actual &&
-	test_cmp expected actual
+test_expect_success 'grep -G -F -P -E pattern' '
+	>empty &&
+	test_must_fail git grep -G -F -P -E "a\x{2b}b\x{2a}c" ab >actual &&
+	test_cmp empty actual
 '
 
-test_expect_success LIBPCRE 'grep -E -G -F -P pattern' '
-	echo ab:a+b >expected &&
-	git grep -E -G -F -P a\\+b >actual &&
+test_expect_success LIBPCRE 'grep -G -F -E -P pattern' '
+	echo "ab:a+b*c" >expected &&
+	git grep -G -F -E -P "a\x{2b}b\x{2a}c" ab >actual &&
 	test_cmp expected actual
 '
 
diff --git a/transport.c b/transport.c
index 1a3998ee51..c9c8056f9d 100644
--- a/transport.c
+++ b/transport.c
@@ -156,7 +156,7 @@ static void set_upstreams(struct transport *transport, struct ref *refs,
 			continue;
 		if (!ref->peer_ref)
 			continue;
-		if (!ref->new_sha1 || is_null_sha1(ref->new_sha1))
+		if (is_null_sha1(ref->new_sha1))
 			continue;
 
 		/* Follow symbolic refs (mainly for HEAD). */