Fix potential crash in color ramp shader

nyalldawson · nyalldawson · commit f3650e6bb484 · 2018-07-20T15:10:37.000+10:00
Fixes #19445
diff --git a/src/core/raster/qgscolorrampshader.cpp b/src/core/raster/qgscolorrampshader.cpp
@@ -359,6 +359,9 @@ bool QgsColorRampShader::shade( double value, int *returnRedValue, int *returnGr
     mLUTInitialized = true;
   }
 
+  if ( mLUT.empty() )
+    return false;
+
   // overflow indicates that value > maximum value + DOUBLE_DIFF_THRESHOLD
   // that way idx can point to the last valid item
   bool overflow = false;

Original file line number	Diff line number	Diff line change
`@@ -359,6 +359,9 @@ bool QgsColorRampShader::shade( double value, int returnRedValue, int returnGr`
`359`	`359`	`mLUTInitialized = true;`
`360`	`360`	`}`
`361`	`361`
	`362`	`+ if ( mLUT.empty() )`
	`363`	`+ return false;`
	`364`	`+`
`362`	`365`	`// overflow indicates that value > maximum value + DOUBLE_DIFF_THRESHOLD`
`363`	`366`	`// that way idx can point to the last valid item`
`364`	`367`	`bool overflow = false;`