Revert "Revert "Disallow readPixels() conversions from untagged srcs to tagged dsts""

This reverts commit 8461506c8b025522eb89cd754c63fb5dbf0cb7f1.

Reason for revert: Fixed some Chrome code, let's try this again.

Original change's description:
> Revert "Disallow readPixels() conversions from untagged srcs to tagged dsts"
> 
> This reverts commit ccfd1083a7b9d546735ddd1037f3240635cce72d.
> 
> Reason for revert: Roll is failing.
> 
> Original change's description:
> > Disallow readPixels() conversions from untagged srcs to tagged dsts
> > 
> > This might break the roll into Chrome.  But let's see how.
> > 
> > BUG=skia:6021
> > 
> > Change-Id: I2698b5d6fe72d01bed0dc64703b592a03d441a80
> > Reviewed-on: https://skia-review.googlesource.com/7127
> > Reviewed-by: Mike Reed <reed@google.com>
> > Commit-Queue: Matt Sarett <msarett@google.com>
> > 
> 
> TBR=msarett@google.com,brianosman@google.com,reed@google.com
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=skia:6021
> 
> Change-Id: I4b62178fd7c23f43cf69ca69fc14526ecd503956
> Reviewed-on: https://skia-review.googlesource.com/7205
> Commit-Queue: Matt Sarett <msarett@google.com>
> Reviewed-by: Matt Sarett <msarett@google.com>
> 

TBR=msarett@google.com,brianosman@google.com,reed@google.com
# Not skipping CQ checks because original CL landed > 1 day ago.
BUG=skia:6021

Change-Id: I3f3f33fe6b84fbd5c537b60ed5c8b9201d529a6a
Reviewed-on: https://skia-review.googlesource.com/8156
Commit-Queue: Matt Sarett <msarett@google.com>
Reviewed-by: Matt Sarett <msarett@google.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/src/core/SkImageInfoPriv.h b/src/core/SkImageInfoPriv.h
index 7fea296d38..a3e449a3d6 100644
--- a/src/core/SkImageInfoPriv.h
+++ b/src/core/SkImageInfoPriv.h
@@ -50,6 +50,8 @@ static inline bool SkImageInfoIsValid(const SkImageInfo& info) {
  *      should we use kPremul or kUnpremul color values with the opaque alphas?  Or should
  *      we just use whatever the |src| alpha is?  In the future, we could choose to clearly
  *      define this, but currently no one is asking for this feature.
+ *      We will not convert to a particular color space if |src| is nullptr.  The color space
+ *      conversion is not well-defined.
  */
 static inline bool SkImageInfoValidConversion(const SkImageInfo& dst, const SkImageInfo& src) {
     if (!SkImageInfoIsValid(dst) || !SkImageInfoIsValid(src)) {
@@ -72,5 +74,9 @@ static inline bool SkImageInfoValidConversion(const SkImageInfo& dst, const SkIm
         return false;
     }
 
+    if (dst.colorSpace() && !src.colorSpace()) {
+        return false;
+    }
+
     return true;
 }