Fix #7887, use actual instead of reported size for script data

CHANGELOG.md

@@ -158,6 +158,7 @@
     Bug #7841: Editor: "Dirty" water heights are saved in modified CELLs
     Bug #7859: AutoCalc flag is not used to calculate potion value
     Bug #7872: Region sounds use wrong odds
+    Bug #7887: Editor: Mismatched reported script data size and actual data size causes a crash during save
     Feature #2566: Handle NAM9 records for manual cell references
     Feature #3537: Shader-based water ripples
     Feature #5173: Support for NiFogProperty

components/esm3/loadscpt.cpp

@@ -149,6 +149,8 @@ namespace ESM
 
         if (!hasHeader)
             esm.fail("Missing SCHD subrecord");
+        // Reported script data size is not always trustworthy, so override it with actual data size
+        mData.mScriptDataSize = mScriptData.size();
     }
 
     void Script::save(ESMWriter& esm, bool isDeleted) const