Merge remote-tracking branch 'origin/GP-4165_ghidra1_ProgramUpgradeCacheImprovement--SQUASHED'

Author: ryanmkurtz

Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/progmgr/ProgramManagerPlugin.java

@@ -304,11 +304,9 @@ private Program openCachedProgram(ProgramLocator locator, Object consumer) {
 		program = programMgr.getOpenProgram(locator);
 		if (program != null) {
 			program.addConsumer(consumer);
-			if (!program.isChanged()) {
-				// Don't put modified programs into the cache.
-				//   NOTE: This will prevent upgraded programs from being added to the cache
-				//   which are already open in the tool.  This could be improved if we could
-				//   distinguish between upgrade and non-upgrade changes.
+			if (!program.isChanged() || ProgramUtilities.isChangedWithUpgradeOnly(program)) {
+				// Don't put modified programs into the cache unless the only change
+				// corresponds to an upgrade during its instantiation.
 				programCache.put(locator, program);
 			}
 			return program;

Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/util/ProgramUtilities.java

@@ -15,6 +15,8 @@
  */
 package ghidra.program.util;
 
+import java.util.*;
+
 import ghidra.program.model.address.Address;
 import ghidra.program.model.listing.*;
 import ghidra.program.model.mem.MemoryAccessException;
@@ -23,8 +25,6 @@
 import ghidra.util.exception.DuplicateNameException;
 import ghidra.util.exception.InvalidInputException;
 
-import java.util.*;
-
 /**
  * General utility class that provides convenience methods
  * to deal with Program objects. 
@@ -173,4 +173,18 @@ public static void convertFunctionWrappedExternalPointer(Symbol functionSymbol)
 			Msg.error(ProgramUtilities.class, "Unexpected Exception", e);
 		}
 	}
+
+	/**
+	 * Determine if a program has a single unsaved change which corresponds to an
+	 * upgrade which occured during instantiation.
+	 * @param program the program to be checked for an unsaved upgrade condition.
+	 * @return true if program upgraded and has not been saved, else false
+	 */
+	public static boolean isChangedWithUpgradeOnly(Program program) {
+		// The only non-undoable change is an upgrade that occurs during instantiation
+		if (!program.isChanged()) {
+			return false;
+		}
+		return !program.canUndo();
+	}
 }