From e55b6fa4d3c5b7e08d9e4bc8c803a79ca908b5a4 Mon Sep 17 00:00:00 2001
From: Marti Maria <marti.maria@littlecms.com>
Date: Tue, 16 May 2023 16:32:42 +0200
Subject: add a check for cmsFLAGS_COPY_ALPHA

Thanks to ISOZAKI Nozomi to point out the issue.
---
 src/cmsxform.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

(limited to 'src')

diff --git a/src/cmsxform.c b/src/cmsxform.c
index c70b7cb..93e07f8 100644
--- a/src/cmsxform.c
+++ b/src/cmsxform.c
@@ -989,6 +989,19 @@ _cmsTRANSFORM* AllocEmptyTransform(cmsContext ContextID, cmsPipeline* lut,
         }
     }
 
+    /**
+    * Check consistency for alpha channel copy
+    */
+    if (*dwFlags & cmsFLAGS_COPY_ALPHA)
+    {
+        if (T_EXTRA(*InputFormat) != T_EXTRA(*OutputFormat))
+        {
+            cmsSignalError(ContextID, cmsERROR_NOT_SUITABLE, "Mismatched alpha channels");
+            cmsDeleteTransform(p);
+            return NULL;
+        }
+    }
+
     p ->InputFormat     = *InputFormat;
     p ->OutputFormat    = *OutputFormat;
     p ->dwOriginalFlags = *dwFlags;
-- 
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