Merge pull request #2274 from keymanapp/web-2261-nul-context-replacement

[Web] Bounds-check on context deletion from keyboard rules

web/source/dom/contentEditable.ts

@@ -144,6 +144,11 @@ namespace com.keyman.dom {
 
       let start = this.getCarets().start;
 
+      // Bounds-check on the number of chars to delete.
+      if(dn > start.offset) {
+        dn = start.offset;
+      }
+
       if(start.node.nodeType != 3) {
         console.warn("Deletion of characters requested without available context!");
         return; // No context to delete characters from.

web/source/dom/designIFrame.ts

@@ -150,6 +150,11 @@ namespace com.keyman.dom {
 
       let start = this.getCarets().start;
 
+      // Bounds-check on the number of chars to delete.
+      if(dn > start.offset) {
+        dn = start.offset;
+      }
+
       if(start.node.nodeType != 3) {
         console.warn("Deletion of characters requested without available context!");
         return; // No context to delete characters from.

web/source/dom/input.ts

@@ -113,6 +113,10 @@ namespace com.keyman.dom {
         let curText = this.getTextBeforeCaret();
         let caret = this.getCaret();
 
+        if(dn > caret) {
+          dn = caret;
+        }
+
         this.adjustDeadkeys(-dn);
         this.setTextBeforeCaret(curText.kmwSubstring(0, this.getCaret() - dn));
         this.setCaret(caret - dn);

web/source/dom/textarea.ts

@@ -141,6 +141,10 @@ namespace com.keyman.dom {
         let curText = this.getTextBeforeCaret();
         let caret = this.getCaret();
 
+        if(dn > caret) {
+          dn = caret;
+        }
+        
         this.adjustDeadkeys(-dn);
         this.setTextBeforeCaret(curText.kmwSubstring(0, this.getCaret() - dn));
         this.setCaret(caret - dn);

web/source/dom/touchAlias.ts

@@ -50,6 +50,9 @@ namespace com.keyman.dom {
     deleteCharsBeforeCaret(dn: number): void {
       if(dn > 0) {
         let curText = this.getTextBeforeCaret();
+        if(this.getDeadkeyCaret() < dn) {
+          dn = this.getDeadkeyCaret();
+        }
         this.adjustDeadkeys(-dn);
         this.root.setTextBeforeCaret(curText.kmwSubstring(0, this.root.getTextCaret() - dn));
       }

web/source/text/kbdInterface.ts

@@ -842,7 +842,9 @@ namespace com.keyman.text {
       // We want to control exactly which deadkeys get removed.
       if(dn > 0) {
         context = this._BuildExtendedContext(dn, dn, outputTarget);
-        for(var i=0; i < context.deadContext.length; i++) {
+        let nulCount = 0;
+
+        for(var i=0; i < context.valContext.length; i++) {
           var dk = context.deadContext[i];
 
           if(dk) {
@@ -851,8 +853,18 @@ namespace com.keyman.text {
 
             // Reduce our reported context size.
             dn--;
+          } else if(context.valContext[i] == "\uFFFE") {
+            // Count any `nul` sentinels that would contribute to our deletion count.
+            nulCount++;
           }
         }
+
+        // Prevent attempts to delete nul sentinels, as they don't exist in the actual context.
+        // (Addresses regression from KMW v 12.0 paired with Developer bug through same version)
+        let contextLength = context.valContext.length - nulCount;
+        if(dn > contextLength) {
+          dn = contextLength;
+        }
       }
 
       // If a matched deadkey hasn't been deleted, we don't WANT to delete it.

web/source/text/outputTarget.ts

@@ -329,6 +329,9 @@ namespace com.keyman.text {
 
     deleteCharsBeforeCaret(dn: number): void {
       if(dn >= 0) {
+        if(dn > this.caretIndex) {
+          dn = this.caretIndex;
+        }
         this.text = this.text.kmwSubstr(0, this.caretIndex - dn) + this.getTextAfterCaret();
         this.caretIndex -= dn;
       }

web/unit_tests/cases/element_interfaces.js

@@ -31,6 +31,7 @@ if(typeof InterfaceTests == 'undefined') {
 
     InterfaceTests.Input.resetWithText = function(pair, string) {
       pair.elem.value = string;
+      pair.wrapper.invalidateSelection();
       pair.elem.setSelectionRange(0, 0);
     }
 
@@ -76,6 +77,7 @@ if(typeof InterfaceTests == 'undefined') {
 
     InterfaceTests.TextArea.resetWithText = function(pair, string) {
       pair.elem.value = string;
+      pair.wrapper.invalidateSelection();
       pair.elem.setSelectionRange(0, 0);
     }
 
@@ -803,6 +805,14 @@ if(typeof InterfaceTests == 'undefined') {
       pair.wrapper.deleteCharsBeforeCaret(2);
       assert.equal(pair.wrapper.getText(), Apple.mixed.substr(0, 1) + Apple.mixed.substr(4), "Error deleting context chars from a mixed SMP string");
       String.kmwEnableSupplementaryPlane(false);
+
+      String.kmwEnableSupplementaryPlane(false);
+      testObj.resetWithText(pair, Apple.normal);
+      testObj.setCaret(pair, 4);
+      pair.wrapper.deleteCharsBeforeCaret(7);
+      assert.equal(pair.wrapper.getText(), "e", "Bounds-check on deletion range failed; context improperly deleted.");
+      String.kmwEnableSupplementaryPlane(false);
+      pair.wrapper.invalidateSelection();
     }
 
     InterfaceTests.Tests.deleteCharsBeforeCaretWithSelection = function(testObj) {