Allow other than /Yes and /Off in a check box (fixes qpdf#1056)

ChangeLog

@@ -1,3 +1,9 @@
+2023-12-22  Jay Berkenbilt  <[email protected]>
+
+	* When setting a check box value, allow any value other than /Off
+	to mean checked. This is permitted by the spec. Previously, any
+	value other than /Yes or /Off was rejected. Fixes #1056.
+
 2023-12-21  Jay Berkenbilt  <[email protected]>
 
 	* Fix to QPDF JSON: a floating point number that appears in

libqpdf/QPDFFormFieldObjectHelper.cc

@@ -304,10 +304,10 @@ QPDFFormFieldObjectHelper::setV(QPDFObjectHandle value, bool need_appearances)
             bool okay = false;
             if (value.isName()) {
                 std::string name = value.getName();
-                if ((name == "/Yes") || (name == "/Off")) {
-                    okay = true;
-                    setCheckBoxValue((name == "/Yes"));
-                }
+                okay = true;
+                // Accept any value other than /Off to mean checked. Files have been seen that use
+                // /1 or other values.
+                setCheckBoxValue((name != "/Off"));
             }
             if (!okay) {
                 this->oh.warnIfPossible("ignoring attempt to set a checkbox field to a value of "

manual/release-notes.rst

@@ -56,6 +56,11 @@ Planned changes for future 12.x (subject to change):
       in scientific notation to fixed-point notation since PDF doesn't
       accept scientific notation.
 
+    - When setting a check box value, allow any value other than
+      ``/Off`` to mean checked. This is permitted by the spec.
+      Previously, any value other than ``/Yes`` or ``/Off`` was
+      rejected.
+
   - Build Enhancements:
 
     - The qpdf test suite now passes when qpdf is linked with an