add a check for cmsFLAGS_COPY_ALPHAHEADmaster

Thanks to ISOZAKI Nozomi to point out the issue.

2 files changed, 29 insertions, 2 deletions

diff --git a/plugins/fast_float/src/fast_float_sup.c b/plugins/fast_float/src/fast_float_sup.c
index a3362b4..2955525 100644
--- a/plugins/fast_float/src/fast_float_sup.c
+++ b/plugins/fast_float/src/fast_float_sup.c
@@ -22,7 +22,6 @@
 
 #include "fast_float_internal.h"
 
-
 // This is the main dispatcher
 static
 cmsBool Floating_Point_Transforms_Dispatcher(_cmsTransform2Fn* TransformFn,
@@ -39,6 +38,9 @@ cmsBool Floating_Point_Transforms_Dispatcher(_cmsTransform2Fn* TransformFn,
     // Special flags for reversing are not supported
     if (T_FLAVOR(*InputFormat) || T_FLAVOR(*OutputFormat)) return FALSE;
 
+    // Check consistency for alpha channel copy
+    if (*dwFlags & cmsFLAGS_COPY_ALPHA && (T_EXTRA(*InputFormat) != T_EXTRA(*OutputFormat))) return FALSE;        
+
     // Try to optimize as a set of curves plus a matrix plus a set of curves
     if (OptimizeMatrixShaper15(TransformFn, UserData, FreeUserData, Lut, InputFormat, OutputFormat, dwFlags)) return TRUE;
 
diff --git a/plugins/fast_float/testbed/fast_float_testbed.c b/plugins/fast_float/testbed/fast_float_testbed.c
index f00b4cf..5e4fb4d 100644
--- a/plugins/fast_float/testbed/fast_float_testbed.c
+++ b/plugins/fast_float/testbed/fast_float_testbed.c
@@ -1142,10 +1142,33 @@ void CheckLab2Roundtrip(void)
 
 }
 
+static
+void CheckAlphaDetect(void)
+{
+    cmsHPROFILE hsRGB;
+    cmsHTRANSFORM xform;
+
+    cmsSetLogErrorHandler(NULL);
+
+    hsRGB = cmsCreate_sRGBProfile();
+    
+    xform = cmsCreateTransform(hsRGB, TYPE_RGB_FLT, hsRGB, TYPE_RGBA_FLT, INTENT_PERCEPTUAL, cmsFLAGS_COPY_ALPHA);
+    cmsCloseProfile(hsRGB);
+
+    if (xform != NULL)
+        Fail("Copy alpha with mismatched channels should not succeed");
+
+    cmsSetLogErrorHandler(FatalErrorQuit);
+}
+
 // Convert some known values
 static
 void CheckConversionFloat(void)
 {
+    trace("Check alpha detection.");
+    CheckAlphaDetect();
+    trace("Ok\n");
+
     trace("Crash test.");
     TryAllValuesFloatAlpha(cmsOpenProfileFromFile(PROFILES_DIR "test5.icc", "r"), cmsOpenProfileFromFile(PROFILES_DIR "test0.icc", "r"), INTENT_PERCEPTUAL, FALSE);
 
@@ -1186,6 +1209,8 @@ void CheckConversionFloat(void)
     TryAllValuesFloatVs16(cmsOpenProfileFromFile(PROFILES_DIR "test0.icc", "r"), cmsOpenProfileFromFile(PROFILES_DIR "test0.icc", "r"), INTENT_PERCEPTUAL);
     TryAllValuesFloat(cmsOpenProfileFromFile(PROFILES_DIR "test0.icc", "r"), cmsOpenProfileFromFile(PROFILES_DIR "test0.icc", "r"), INTENT_PERCEPTUAL);
     trace("Ok\n");
+
+
 }
 
 
@@ -2470,7 +2495,7 @@ int main()
        trace("Installing plug-in ... ");
        cmsPlugin(cmsFastFloatExtensions());
        trace("done.\n\n");
-                    
+                      
        CheckComputeIncrements();
 
        // 15 bit functionality