net/netip: fix uses of "IPv4-mapped IPv6" in doc comments

The correct (or at least mostly commonly used) name for addresses of the
form ::ffff:192.0.2.128 is "IPv4-mapped IPv6". Some of the comments in
the netip package used that name, but others used "IPv6-mapped IPv4" or
"v6-mapped". This change makes the usage of the term consistent.

Change-Id: Ic01309ddf9252705a2387322d940b777e88800a5
GitHub-Last-Rev: 56044dc
GitHub-Pull-Request: #51950
Reviewed-on: https://go-review.googlesource.com/c/go/+/395914
Reviewed-by: Damien Neil <[email protected]>
Trust: Damien Neil <[email protected]>
Run-TryBot: Damien Neil <[email protected]>
TryBot-Result: Gopher Robot <[email protected]>
Trust: Ian Lance Taylor <[email protected]>

Author: adam-p

src/net/netip/netip.go

@@ -90,7 +90,7 @@ func AddrFrom4(addr [4]byte) Addr {
 }
 
 // AddrFrom16 returns the IPv6 address given by the bytes in addr.
-// An IPv6-mapped IPv4 address is left as an IPv6 address.
+// An IPv4-mapped IPv6 address is left as an IPv6 address.
 // (Use Unmap to convert them if needed.)
 func AddrFrom16(addr [16]byte) Addr {
 	return Addr{
@@ -675,7 +675,7 @@ const (
 )
 
 // As16 returns the IP address in its 16-byte representation.
-// IPv4 addresses are returned in their v6-mapped form.
+// IPv4 addresses are returned in their IPv4-mapped IPv6 form.
 // IPv6 addresses with zones are returned without their zone (use the
 // Zone method to get it).
 // The ip zero value returns all zeroes.
@@ -1340,7 +1340,7 @@ func (p Prefix) Masked() Prefix {
 // Contains reports whether the network p includes ip.
 //
 // An IPv4 address will not match an IPv6 prefix.
-// A v6-mapped IPv6 address will not match an IPv4 prefix.
+// An IPv4-mapped IPv6 address will not match an IPv4 prefix.
 // A zero-value IP will not match any prefix.
 // If ip has an IPv6 zone, Contains returns false,
 // because Prefixes strip zones.
@@ -1372,8 +1372,8 @@ func (p Prefix) Contains(ip Addr) bool {
 // Overlaps reports whether p and o contain any IP addresses in common.
 //
 // If p and o are of different address families or either have a zero
-// IP, it reports false. Like the Contains method, a prefix with a
-// v6-mapped IPv4 IP is still treated as an IPv6 mask.
+// IP, it reports false. Like the Contains method, a prefix with an
+// IPv4-mapped IPv6 IP is still treated as an IPv6 mask.
 func (p Prefix) Overlaps(o Prefix) bool {
 	if !p.IsValid() || !o.IsValid() {
 		return false

src/net/netip/netip_test.go

@@ -1776,7 +1776,7 @@ func TestPrefixOverlaps(t *testing.T) {
 		{pfx("1::1/128"), pfx("2::2/128"), false},
 		{pfx("0100::0/8"), pfx("::1/128"), false},
 
-		// v6-mapped v4 should not overlap with IPv4.
+		// IPv4-mapped IPv6 should not overlap with IPv4.
 		{PrefixFrom(AddrFrom16(mustIP("1.2.0.0").As16()), 16), pfx("1.2.3.0/24"), false},
 
 		// Invalid prefixes