From cfb2cc057c32330be0ca0a68cfbd245cb2b8e31b Mon Sep 17 00:00:00 2001
From: Tulir Asokan <tulir@maunium.net>
Date: Wed, 5 Sep 2018 10:55:48 +0300
Subject: Update to latest gomatrix. Things are broken

---
 .../github.com/lucasb-eyer/go-colorful/README.md   | 33 ++++++++++++++--------
 .../github.com/lucasb-eyer/go-colorful/colors.go   |  7 +++--
 2 files changed, 26 insertions(+), 14 deletions(-)

(limited to 'vendor/github.com/lucasb-eyer')

diff --git a/vendor/github.com/lucasb-eyer/go-colorful/README.md b/vendor/github.com/lucasb-eyer/go-colorful/README.md
index c170435..8c89c38 100644
--- a/vendor/github.com/lucasb-eyer/go-colorful/README.md
+++ b/vendor/github.com/lucasb-eyer/go-colorful/README.md
@@ -124,17 +124,16 @@ Because a `colorful.Color` implements Go's `color.Color` interface (found in the
 `image/color` package), it can be used anywhere that expects a `color.Color`.
 
 Furthermore, you can convert anything that implements the `color.Color` interface
-into a `colorful.Color` using the `MakeColorful` function:
+into a `colorful.Color` using the `MakeColor` function:
 
 ```go
-c := colorful.MakeColor(color.Gray16{12345})
+c, ok := colorful.MakeColor(color.Gray16{12345})
 ```
 
-**Caveat:** Be aware that for this latter conversion  (using `MakeColor`) hits a corner-case
-when alpha is exactly zero. Because `color.Color` uses pre-multiplied alpha colors,
-this means the RGB values are lost and it's impossible to recover them. The current
-implementation `panic()`s in that case, see [issue 21](https://github.com/lucasb-eyer/go-colorful/issues/21)
-for discussion and suggesting alternatives.
+**Caveat:** Be aware that this latter conversion (using `MakeColor`) hits a
+corner-case when alpha is exactly zero. Because `color.Color` uses pre-multiplied
+alpha colors, this means the RGB values are lost (set to 0) and it's impossible
+to recover them. In such a case `MakeColor` will return `false` as its second value.
 
 ### Comparing colors
 In the RGB color space, the Euclidian distance between colors *doesn't* correspond
@@ -456,16 +455,26 @@ but that is outside the scope of this library.
 Thanks to [@ZirconiumX](https://github.com/ZirconiumX) for starting this investigation,
 see [issue #18](https://github.com/lucasb-eyer/go-colorful/issues/18) for details.
 
-### Q: `MakeColor` panics when alpha is zero!
-A: Because in that case, the conversion is undefined. See
-[issue 21](https://github.com/lucasb-eyer/go-colorful/issues/21)
-as well as the short caveat discussion in the ["The `color.Color` interface"](README.md#the-colorcolor-interface) section above.
+### Q: Why would `MakeColor` ever fail!?
+A: `MakeColor` fails when the alpha channel is zero. In that case, the
+conversion is undefined. See [issue 21](https://github.com/lucasb-eyer/go-colorful/issues/21)
+as well as the short caveat note in the ["The `color.Color` interface"](README.md#the-colorcolor-interface)
+section above.
 
 Who?
 ====
 
 This library has been developed by Lucas Beyer with contributions from
-Bastien Dejean (@baskerville) and Phil Kulak (@pkulak).
+Bastien Dejean (@baskerville), Phil Kulak (@pkulak) and Christian Muehlhaeuser (@muesli).
+
+Release Notes
+=============
+
+### Version 1.0
+- API Breaking change in `MakeColor`: instead of `panic`ing when alpha is zero, it now returns a secondary, boolean return value indicating success. See [the color.Color interface](https://github.com/lucasb-eyer/go-colorful#the-colorcolor-interface) section and [this FAQ entry](https://github.com/lucasb-eyer/go-colorful#q-why-would-makecolor-ever-fail) for details.
+
+### Version 0.9
+- Initial version number after having ignored versioning for a long time :)
 
 License: MIT
 ============
diff --git a/vendor/github.com/lucasb-eyer/go-colorful/colors.go b/vendor/github.com/lucasb-eyer/go-colorful/colors.go
index 7469cf7..febf94c 100644
--- a/vendor/github.com/lucasb-eyer/go-colorful/colors.go
+++ b/vendor/github.com/lucasb-eyer/go-colorful/colors.go
@@ -22,8 +22,11 @@ func (col Color) RGBA() (r, g, b, a uint32) {
 }
 
 // Constructs a colorful.Color from something implementing color.Color
-func MakeColor(col color.Color) Color {
+func MakeColor(col color.Color) (Color, bool) {
 	r, g, b, a := col.RGBA()
+	if a == 0 {
+		return Color{0, 0, 0}, false
+	}
 
 	// Since color.Color is alpha pre-multiplied, we need to divide the
 	// RGB values by alpha again in order to get back the original RGB.
@@ -34,7 +37,7 @@ func MakeColor(col color.Color) Color {
 	b *= 0xffff
 	b /= a
 
-	return Color{float64(r) / 65535.0, float64(g) / 65535.0, float64(b) / 65535.0}
+	return Color{float64(r) / 65535.0, float64(g) / 65535.0, float64(b) / 65535.0}, true
 }
 
 // Might come in handy sometimes to reduce boilerplate code.
-- 
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