diff --git a/apps/graph/base.fr.i18n b/apps/graph/base.fr.i18n
index 5014969aa..2d4af4a84 100644
--- a/apps/graph/base.fr.i18n
+++ b/apps/graph/base.fr.i18n
@@ -12,14 +12,14 @@ Zeros = "Zéros"
 Tangent = "Tangente"
 Intersection = "Intersection"
 Preimage = "Antécédent"
-SelectLowerBound = "Selectionner la borne inférieure"
-SelectUpperBound = "Selectionner la borne supérieure"
+SelectLowerBound = "Sélectionner la borne inférieure"
+SelectUpperBound = "Sélectionner la borne supérieure"
 NoMaximumFound = "Aucun maximum trouvé"
 NoMinimumFound = "Aucun minimum trouvé"
 NoZeroFound = "Aucun zéro trouvé"
 NoIntersectionFound = "Aucune intersection trouvée"
 NoPreimageFound = "Aucun antécédent trouvé"
-DerivativeFunctionColumn = "Colonne de la fonction derivée"
-HideDerivativeColumn = "Masquer la fonction derivée"
+DerivativeFunctionColumn = "Colonne de la fonction dérivée"
+HideDerivativeColumn = "Masquer la fonction dérivée"
 AllowedCharactersAZaz09 = "Caractères autorisés : A-Z, a-z, 0-9, _"
 ReservedName = "Nom réservé"
diff --git a/apps/settings/base.fr.i18n b/apps/settings/base.fr.i18n
index c76912acc..9a6cc3547 100644
--- a/apps/settings/base.fr.i18n
+++ b/apps/settings/base.fr.i18n
@@ -20,6 +20,6 @@ Cartesian = "Algébrique "
 Polar = "Exponentielle "
 Brightness = "Luminosité"
 SoftwareVersion = "Version du logiciel"
-SerialNumber = "Numéro serie"
+SerialNumber = "Numéro série"
 UpdatePopUp = "Rappel mise à jour"
 BetaPopUp = "Rappel version bêta"
diff --git a/apps/solver/solutions_controller.cpp b/apps/solver/solutions_controller.cpp
index 77e2138e4..dcb422691 100644
--- a/apps/solver/solutions_controller.cpp
+++ b/apps/solver/solutions_controller.cpp
@@ -79,7 +79,7 @@ SolutionsController::SolutionsController(Responder * parentResponder, EquationSt
 {
   m_delta2Layout = HorizontalLayout::Builder(VerticalOffsetLayout::Builder(CodePointLayout::Builder('2', KDFont::SmallFont), VerticalOffsetLayoutNode::Position::Superscript), LayoutHelper::String("-4ac", 4, KDFont::SmallFont));
   const char * deltaB = "Δ=b";
-  static_cast<HorizontalLayout&>(m_delta2Layout).addOrMergeChildAtIndex(LayoutHelper::String(deltaB, 3, KDFont::SmallFont), 0, false);
+  static_cast<HorizontalLayout&>(m_delta2Layout).addOrMergeChildAtIndex(LayoutHelper::String(deltaB, strlen(deltaB), KDFont::SmallFont), 0, false);
   for (int i = 0; i < EquationStore::k_maxNumberOfExactSolutions; i++) {
     m_exactValueCells[i].setParentResponder(m_contentView.selectableTableView());
   }
diff --git a/apps/statistics/histogram_controller.cpp b/apps/statistics/histogram_controller.cpp
index 70d02ac1d..fcd94ed73 100644
--- a/apps/statistics/histogram_controller.cpp
+++ b/apps/statistics/histogram_controller.cpp
@@ -90,6 +90,20 @@ Responder * HistogramController::tabController() const {
   return (parentResponder()->parentResponder()->parentResponder()->parentResponder());
 }
 
+void pad(char * buffer, int bufferSize, int * currentNumberOfChar, int maxGlyphLengthWithPadding) {
+  assert(*currentNumberOfChar <= bufferSize);
+  size_t currentGlyphLength = UTF8Helper::StringGlyphLength(buffer, *currentNumberOfChar);
+  bool addedPadding = false;
+  while (currentGlyphLength < maxGlyphLengthWithPadding && *currentNumberOfChar < bufferSize) {
+    *currentNumberOfChar = *currentNumberOfChar + UTF8Decoder::CodePointToChars(' ', buffer + *currentNumberOfChar, bufferSize - *currentNumberOfChar);
+    addedPadding = true;
+    currentGlyphLength++;
+  }
+  if (addedPadding) {
+    buffer[*currentNumberOfChar-1] = 0;
+  }
+}
+
 void HistogramController::reloadBannerView() {
   if (selectedSeriesIndex() < 0) {
     return;
@@ -107,7 +121,7 @@ void HistogramController::reloadBannerView() {
   // Add lower bound
   if (selectedSeriesIndex() >= 0) {
     double lowerBound = m_store->startOfBarAtIndex(selectedSeriesIndex(), *m_selectedBarIndex);
-    numberOfChar += PoincareHelpers::ConvertFloatToText<double>(lowerBound, buffer+numberOfChar, PrintFloat::bufferSizeForFloatsWithPrecision(Constant::LargeNumberOfSignificantDigits), Constant::LargeNumberOfSignificantDigits);
+    numberOfChar += PoincareHelpers::ConvertFloatToText<double>(lowerBound, buffer+numberOfChar, bufferSize-numberOfChar, Constant::LargeNumberOfSignificantDigits);
   }
 
   numberOfChar+= UTF8Decoder::CodePointToChars(';', buffer + numberOfChar, bufferSize - numberOfChar);
@@ -115,15 +129,12 @@ void HistogramController::reloadBannerView() {
   // Add upper bound
   if (selectedSeriesIndex() >= 0) {
     double upperBound = m_store->endOfBarAtIndex(selectedSeriesIndex(), *m_selectedBarIndex);
-    numberOfChar += PoincareHelpers::ConvertFloatToText<double>(upperBound, buffer+numberOfChar, PrintFloat::bufferSizeForFloatsWithPrecision(Constant::LargeNumberOfSignificantDigits), Constant::LargeNumberOfSignificantDigits);
+    numberOfChar += PoincareHelpers::ConvertFloatToText<double>(upperBound, buffer+numberOfChar, bufferSize-numberOfChar, Constant::LargeNumberOfSignificantDigits);
   }
   numberOfChar+= UTF8Decoder::CodePointToChars('[', buffer + numberOfChar, bufferSize - numberOfChar);
 
   // Padding
-  for (int i = numberOfChar; i < k_maxIntervalLegendLength; i++) {
-    numberOfChar+= UTF8Decoder::CodePointToChars(' ', buffer + numberOfChar, bufferSize - numberOfChar);
-  }
-  buffer[k_maxIntervalLegendLength] = 0;
+  pad(buffer, bufferSize, &numberOfChar, k_maxIntervalLegendLength);
   m_view.bannerView()->intervalView()->setText(buffer);
 
   // Add Size Data
@@ -135,13 +146,10 @@ void HistogramController::reloadBannerView() {
   double size = 0;
   if (selectedSeriesIndex() >= 0) {
     size = m_store->heightOfBarAtIndex(selectedSeriesIndex(), *m_selectedBarIndex);
-    numberOfChar += PoincareHelpers::ConvertFloatToText<double>(size, buffer+numberOfChar, PrintFloat::bufferSizeForFloatsWithPrecision(Constant::LargeNumberOfSignificantDigits), Constant::LargeNumberOfSignificantDigits);
+    numberOfChar += PoincareHelpers::ConvertFloatToText<double>(size, buffer+numberOfChar, bufferSize-numberOfChar, Constant::LargeNumberOfSignificantDigits);
   }
   // Padding
-  for (int i = numberOfChar; i < k_maxLegendLength; i++) {
-    numberOfChar+= UTF8Decoder::CodePointToChars(' ', buffer + numberOfChar, bufferSize - numberOfChar);
-  }
-  buffer[k_maxLegendLength] = 0;
+  pad(buffer, bufferSize, &numberOfChar, k_maxLegendLength);
   m_view.bannerView()->sizeView()->setText(buffer);
 
   // Add Frequency Data
@@ -152,13 +160,10 @@ void HistogramController::reloadBannerView() {
   numberOfChar += legendLength;
   if (selectedSeriesIndex() >= 0) {
     double frequency = size/m_store->sumOfOccurrences(selectedSeriesIndex());
-    numberOfChar += PoincareHelpers::ConvertFloatToText<double>(frequency, buffer+numberOfChar, PrintFloat::bufferSizeForFloatsWithPrecision(Constant::LargeNumberOfSignificantDigits), Constant::LargeNumberOfSignificantDigits);
+    numberOfChar += PoincareHelpers::ConvertFloatToText<double>(frequency, buffer+numberOfChar, bufferSize - numberOfChar, Constant::LargeNumberOfSignificantDigits);
   }
   // Padding
-  for (int i = numberOfChar; i < k_maxLegendLength; i++) {
-    numberOfChar+= UTF8Decoder::CodePointToChars(' ', buffer + numberOfChar, bufferSize - numberOfChar);
-  }
-  buffer[k_maxLegendLength] = 0;
+  pad(buffer, bufferSize, &numberOfChar, k_maxLegendLength);
   m_view.bannerView()->frequencyView()->setText(buffer);
 
   m_view.bannerView()->reload();
diff --git a/escher/include/escher/text_input_helpers.h b/escher/include/escher/text_input_helpers.h
index 04718b4b5..2fa8e2671 100644
--- a/escher/include/escher/text_input_helpers.h
+++ b/escher/include/escher/text_input_helpers.h
@@ -6,7 +6,7 @@
 
 namespace TextInputHelpers {
 
-const char * CursorPositionInCommand(const char * text);
+const char * CursorPositionInCommand(const char * text, const char * stoppingPosition = nullptr);
 /* Returns the pointer to the char that should be right of the cursor, which is
  * the first char between :
  *   - The first EmptyChar (which is the position of the first argument)
diff --git a/escher/src/text_area.cpp b/escher/src/text_area.cpp
index 86bb1d560..e1c73ea97 100644
--- a/escher/src/text_area.cpp
+++ b/escher/src/text_area.cpp
@@ -34,47 +34,62 @@ static inline void InsertSpacesAtLocation(int spacesCount, char * buffer, int bu
 }
 
 bool TextArea::handleEventWithText(const char * text, bool indentation, bool forceCursorRightOfText) {
-  constexpr int bufferSize = TextField::maxBufferSize();
-  char buffer[bufferSize];
-
-  size_t textLength = strlcpy(buffer, text, bufferSize);
-
-  // Add indentation spaces
+  if (*text == 0) {
+    return false;
+  }
+  /* Compute the indentation. If the text cannot be inserted with the
+   * indentation, stop here. */
+  int spacesCount = 0;
+  int totalIndentationSize = 0;
+  int textLen = strlen(text);
+  char * insertionPosition = const_cast<char *>(cursorLocation());
   if (indentation) {
     // Compute the indentation
-    int spacesCount = indentationBeforeCursor();
-    const char * teaxtAreaBuffer = contentView()->text();
-    if (cursorLocation() > teaxtAreaBuffer && UTF8Helper::PreviousCodePointIs(teaxtAreaBuffer, cursorLocation(), ':')) {
+    spacesCount = indentationBeforeCursor();
+    const char * textAreaBuffer = contentView()->text();
+    if (insertionPosition > textAreaBuffer && UTF8Helper::PreviousCodePointIs(textAreaBuffer, insertionPosition, ':')) {
       spacesCount += k_indentationSpaces;
     }
-
     // Check the text will not overflow the buffer
-    int totalIndentationSize = UTF8Helper::CountOccurrences(text, '\n') * spacesCount;
-    if (contentView()->getText()->textLength() + textLength + totalIndentationSize >= contentView()->getText()->bufferSize() || textLength == 0) {
+    totalIndentationSize = UTF8Helper::CountOccurrences(text, '\n') * spacesCount;
+    if (contentView()->getText()->textLength() + textLen + totalIndentationSize >= contentView()->getText()->bufferSize()) {
       return false;
     }
-
-    UTF8Helper::PerformAtCodePoints(
-        buffer, '\n',
-        [](int codePointOffset, void * text, int indentation) {
-          int offset = codePointOffset + UTF8Decoder::CharSizeOfCodePoint('\n');
-          InsertSpacesAtLocation(indentation, (char *)text + offset, TextField::maxBufferSize() - offset); //TODO
-        },
-        [](int c1, void * c2, int c3) {},
-        (void *)buffer,
-        spacesCount);
   }
-  const char * cursorPositionInCommand = TextInputHelpers::CursorPositionInCommand(buffer);
-
-  // Remove the Empty code points
-  UTF8Helper::RemoveCodePoint(buffer, UCodePointEmpty, &cursorPositionInCommand);
 
   // Insert the text
-  if (insertTextAtLocation(buffer, cursorLocation())) {
-    // Set the cursor location
-    const char * nextCursorLocation = cursorLocation() + (forceCursorRightOfText ? strlen(buffer) : cursorPositionInCommand - buffer);
-    setCursorLocation(nextCursorLocation);
+  if (!insertTextAtLocation(text, insertionPosition)) {
+    return true;
   }
+
+  // Insert the indentation
+  if (indentation) {
+    UTF8Helper::PerformAtCodePoints(
+        insertionPosition,
+        '\n',
+        [](int codePointOffset, void * text, int indentation, int bufferLength) {
+          int offset = codePointOffset + UTF8Decoder::CharSizeOfCodePoint('\n');
+          InsertSpacesAtLocation(indentation, (char *)text + offset, bufferLength);
+        },
+        [](int c1, void * c2, int c3, int c4) {},
+        (void *)insertionPosition,
+        spacesCount,
+        contentView()->getText()->bufferSize() - (insertionPosition - contentView()->getText()->text()),
+        UCodePointNull,
+        true,
+        nullptr,
+        insertionPosition + textLen);
+  }
+  const char * endOfInsertedText = insertionPosition + textLen + totalIndentationSize;
+  const char * cursorPositionInCommand = TextInputHelpers::CursorPositionInCommand(insertionPosition, endOfInsertedText);
+
+  // Remove the Empty code points
+  UTF8Helper::RemoveCodePoint(insertionPosition, UCodePointEmpty, &cursorPositionInCommand, endOfInsertedText);
+
+  // Set the cursor location
+  const char * nextCursorLocation = forceCursorRightOfText ? endOfInsertedText : cursorPositionInCommand;
+  setCursorLocation(nextCursorLocation);
+
   return true;
 }
 
@@ -136,14 +151,14 @@ int TextArea::indentationBeforeCursor() const {
    * indentation size when encountering spaces, reset it to 0 when encountering
    * another code point, until reaching the beginning of the line. */
   UTF8Helper::PerformAtCodePoints(const_cast<TextArea *>(this)->contentView()->text(), ' ',
-      [](int codePointOffset, void * indentationSize, int context){
+      [](int codePointOffset, void * indentationSize, int context1, int context2){
         int * castedSize = (int *) indentationSize;
         *castedSize = *castedSize + 1;
       },
-      [](int codePointOffset, void * indentationSize, int context){
+      [](int codePointOffset, void * indentationSize, int context1, int context2){
         *((int *) indentationSize) = 0;
       },
-      &indentationSize, 0, '\n', false, cursorLocation());
+      &indentationSize, 0, -1, '\n', false, cursorLocation());
   return indentationSize;
 }
 
@@ -380,10 +395,10 @@ bool TextArea::TextArea::ContentView::insertTextAtLocation(const char * text, co
   // Scan for \n and 0
   const char * nullLocation = UTF8Helper::PerformAtCodePoints(
       text, '\n',
-      [](int codePointOffset, void * lineBreak, int indentation) {
+      [](int codePointOffset, void * lineBreak, int context1, int context2) {
         *((bool *)lineBreak) = true;
       },
-      [](int c1, void * c2, int c3) { },
+      [](int c1, void * c2, int c3, int c4) { },
       &lineBreak, 0);
 
   assert(UTF8Helper::CodePointIs(nullLocation, 0));
diff --git a/escher/src/text_input_helpers.cpp b/escher/src/text_input_helpers.cpp
index e0801444b..a1847d22e 100644
--- a/escher/src/text_input_helpers.cpp
+++ b/escher/src/text_input_helpers.cpp
@@ -4,11 +4,12 @@
 
 namespace TextInputHelpers {
 
-const char * CursorPositionInCommand(const char * text) {
+const char * CursorPositionInCommand(const char * text, const char * stoppingPosition) {
+  assert(stoppingPosition == nullptr || text <= stoppingPosition);
   UTF8Decoder decoder(text);
   const char * currentPointer = text;
   CodePoint codePoint = decoder.nextCodePoint();
-  while (codePoint != UCodePointNull) {
+  while ((stoppingPosition == nullptr || currentPointer < stoppingPosition) && codePoint != UCodePointNull) {
     if (codePoint == UCodePointEmpty) {
       return currentPointer;
     }
diff --git a/ion/Makefile b/ion/Makefile
index 49131c7b7..5a504ecee 100644
--- a/ion/Makefile
+++ b/ion/Makefile
@@ -40,6 +40,7 @@ tests += $(addprefix ion/test/,\
   keyboard.cpp\
   storage.cpp\
   utf8_decoder.cpp\
+  utf8_helper.cpp\
 )
 
 TEST_EXT_FLASH_REPROGRAM ?= 0
diff --git a/ion/include/ion/unicode/utf8_helper.h b/ion/include/ion/unicode/utf8_helper.h
index 2a665f25c..f24220a27 100644
--- a/ion/include/ion/unicode/utf8_helper.h
+++ b/ion/include/ion/unicode/utf8_helper.h
@@ -24,7 +24,7 @@ void CopyAndRemoveCodePoint(char * dst, size_t dstSize, const char * src, CodePo
 
 /* Remove all code points c. and update an index that should be lower if code
  * points where removed before it. Ensure null-termination of dst. */
-void RemoveCodePoint(char * buffer, CodePoint c, const char * * indexToDUpdate = nullptr);
+void RemoveCodePoint(char * buffer, CodePoint c, const char * * indexToDUpdate = nullptr, const char * stoppingPosition = nullptr);
 
 /* Copy src into dst until end of dst or code point c, with null termination. Return the length of the copy */
 size_t CopyUntilCodePoint(char * dst, size_t dstSize, const char * src, CodePoint c);
@@ -50,8 +50,19 @@ size_t CopyUntilCodePoint(char * dst, size_t dstSize, const char * src, CodePoin
  *    ^start of string  ^r             ^initialPosition
  *
  * */
-typedef void (*CodePointAction)(int codePointOffset, void * contextPointer, int contextInt);
-const char * PerformAtCodePoints(const char * string, CodePoint c, CodePointAction actionCodePoint, CodePointAction actionOtherCodePoint, void * contextPointer, int contextInt, CodePoint stoppingCodePoint = UCodePointNull, bool goingRight = true, const char * initialPosition = nullptr);
+typedef void (*CodePointAction)(int codePointOffset, void * contextPointer, int contextInt1, int contextInt2);
+const char * PerformAtCodePoints(
+    const char * string,
+    CodePoint c,
+    CodePointAction actionCodePoint,
+    CodePointAction actionOtherCodePoint,
+    void * contextPointer,
+    int contextInt1,
+    int contextInt2 = -1,
+    CodePoint stoppingCodePoint = UCodePointNull,
+    bool goingRight = true,
+    const char * initialPosition = nullptr,
+    const char * stoppingPosition = nullptr);
 
 bool PreviousCodePointIs(const char * buffer, const char * location, CodePoint c);
 bool CodePointIs(const char * location, CodePoint c);
@@ -68,6 +79,10 @@ int RemovePreviousCodePoint(const char * text, char * location, CodePoint * c);
 const char * CodePointAtGlyphOffset(const char * buffer, int position);
 size_t GlyphOffsetAtCodePoint(const char * buffer, const char * position);
 
+/* Return the number of glyphs in a string.
+ * For instance, strlen("∑") = 3 but StringGlyphLength("∑") = 1 */
+size_t StringGlyphLength(const char * s, int maxSize = -1);
+
 };
 
 #endif
diff --git a/ion/src/shared/unicode/utf8_helper.cpp b/ion/src/shared/unicode/utf8_helper.cpp
index 51a8bf3ac..a972fc079 100644
--- a/ion/src/shared/unicode/utf8_helper.cpp
+++ b/ion/src/shared/unicode/utf8_helper.cpp
@@ -110,7 +110,7 @@ void CopyAndRemoveCodePoint(char * dst, size_t dstSize, const char * src, CodePo
   *(dst + minInt(bufferIndex, dstSize - 1)) = 0;
 }
 
-void RemoveCodePoint(char * buffer, CodePoint c, const char * * pointerToUpdate) {
+void RemoveCodePoint(char * buffer, CodePoint c, const char * * pointerToUpdate, const char * stoppingPosition) {
   UTF8Decoder decoder(buffer);
   const char * currentPointer = buffer;
   CodePoint codePoint = decoder.nextCodePoint();
@@ -118,7 +118,7 @@ void RemoveCodePoint(char * buffer, CodePoint c, const char * * pointerToUpdate)
   size_t bufferIndex = 0;
   size_t codePointCharSize = UTF8Decoder::CharSizeOfCodePoint(c);
 
-  while (codePoint != UCodePointNull) {
+  while (codePoint != UCodePointNull && (stoppingPosition == nullptr || currentPointer < stoppingPosition)) {
     if (codePoint != c) {
       int copySize = nextPointer - currentPointer;
       memmove(buffer + bufferIndex, currentPointer, copySize);
@@ -131,7 +131,16 @@ void RemoveCodePoint(char * buffer, CodePoint c, const char * * pointerToUpdate)
     codePoint = decoder.nextCodePoint();
     nextPointer = decoder.stringPosition();
   }
-  *(buffer + bufferIndex) = 0;
+  if (codePoint == UCodePointNull) {
+    *(buffer + bufferIndex) = 0;
+  } else {
+    assert(stoppingPosition != nullptr);
+    // Find the null-terminating code point
+    const char * nullTermination = CodePointSearch(currentPointer, UCodePointNull);
+    /* Copy what remains of the buffer after the stopping position for code
+     * point removal */
+    memmove(buffer + bufferIndex, stoppingPosition, nullTermination - stoppingPosition + 1);
+  }
 }
 
 size_t CopyUntilCodePoint(char * dst, size_t dstSize, const char * src, CodePoint c) {
@@ -150,7 +159,7 @@ size_t CopyUntilCodePoint(char * dst, size_t dstSize, const char * src, CodePoin
   return copySize;
 }
 
-const char * PerformAtCodePoints(const char * s, CodePoint c, CodePointAction actionCodePoint, CodePointAction actionOtherCodePoint, void * contextPointer, int contextInt, CodePoint stoppingCodePoint, bool goingRight, const char * initialPosition) {
+const char * PerformAtCodePoints(const char * s, CodePoint c, CodePointAction actionCodePoint, CodePointAction actionOtherCodePoint, void * contextPointer, int contextInt1, int contextInt2, CodePoint stoppingCodePoint, bool goingRight, const char * initialPosition, const char * stoppingPosition) {
   /* If we are decoding towards the left, we must have a starting position. If
    * we are decoding towards the right, the starting position is the start of
    * string. */
@@ -162,22 +171,22 @@ const char * PerformAtCodePoints(const char * s, CodePoint c, CodePointAction ac
      * translations. We can do a classic char search. */
     if (goingRight) {
       const char * i = s;
-      while (*i != stoppingCodePoint && *i != 0) {
+      while (*i != stoppingCodePoint && *i != 0 && i != stoppingPosition) {
         if (*i == c) {
-          actionCodePoint(i - s, contextPointer, contextInt);
+          actionCodePoint(i - s, contextPointer, contextInt1, contextInt2);
         } else {
-          actionOtherCodePoint(i - s, contextPointer, contextInt);
+          actionOtherCodePoint(i - s, contextPointer, contextInt1, contextInt2);
         }
         i++;
       }
       return i;
     }
     const char * i = initialPosition - 1;
-    while (i >= s && *i != stoppingCodePoint) {
+    while (i >= s && *i != stoppingCodePoint && i != stoppingPosition) {
       if (*i == c) {
-        actionCodePoint(i - s, contextPointer, contextInt);
+        actionCodePoint(i - s, contextPointer, contextInt1, contextInt2);
       } else {
-        actionOtherCodePoint(i - s, contextPointer, contextInt);
+        actionOtherCodePoint(i - s, contextPointer, contextInt1, contextInt2);
       }
       i--;
     }
@@ -188,11 +197,11 @@ const char * PerformAtCodePoints(const char * s, CodePoint c, CodePointAction ac
     UTF8Decoder decoder(s);
     const char * codePointPointer = decoder.stringPosition();
     CodePoint codePoint = decoder.nextCodePoint();
-    while (codePoint != stoppingCodePoint && codePoint != UCodePointNull) {
+    while (codePoint != stoppingCodePoint && codePoint != UCodePointNull && codePointPointer != stoppingPosition) {
       if (codePoint == c) {
-        actionCodePoint(codePointPointer - s, contextPointer, contextInt);
+        actionCodePoint(codePointPointer - s, contextPointer, contextInt1, contextInt2);
       } else {
-        actionOtherCodePoint(codePointPointer - s, contextPointer, contextInt);
+        actionOtherCodePoint(codePointPointer - s, contextPointer, contextInt1, contextInt2);
       }
       codePointPointer = decoder.stringPosition();
       codePoint = decoder.nextCodePoint();
@@ -206,11 +215,11 @@ const char * PerformAtCodePoints(const char * s, CodePoint c, CodePointAction ac
   UTF8Decoder decoder(s, initialPosition);
   CodePoint codePoint = decoder.previousCodePoint();
   const char * codePointPointer = decoder.stringPosition();
-  while (codePointPointer >= s && codePoint != stoppingCodePoint) {
+  while (codePointPointer >= s && codePoint != stoppingCodePoint && codePointPointer != stoppingPosition) {
     if (codePoint == c) {
-      actionCodePoint(codePointPointer - s, contextPointer, contextInt);
+      actionCodePoint(codePointPointer - s, contextPointer, contextInt1, contextInt2);
     } else {
-      actionOtherCodePoint(codePointPointer - s, contextPointer, contextInt);
+      actionOtherCodePoint(codePointPointer - s, contextPointer, contextInt1, contextInt2);
     }
     if (codePointPointer > s) {
       codePoint = decoder.previousCodePoint();
@@ -326,5 +335,20 @@ size_t GlyphOffsetAtCodePoint(const char * buffer, const char * position) {
   return glyphIndex;
 }
 
+size_t StringGlyphLength(const char * s, int maxSize) {
+  if (maxSize == 0) {
+    return 0;
+  }
+  UTF8Decoder decoder(s);
+  CodePoint codePoint = decoder.nextCodePoint();
+  size_t glyphIndex = 0;
+  while (codePoint != UCodePointNull && (maxSize < 0 || ((decoder.stringPosition() - s) <= maxSize))) {
+    if (!codePoint.isCombining()) {
+      glyphIndex++;
+    }
+    codePoint = decoder.nextCodePoint();
+  }
+  return glyphIndex;
+}
 
-};
+}
diff --git a/ion/test/utf8_helper.cpp b/ion/test/utf8_helper.cpp
new file mode 100644
index 000000000..975b5cff1
--- /dev/null
+++ b/ion/test/utf8_helper.cpp
@@ -0,0 +1,14 @@
+#include <quiz.h>
+#include <ion/unicode/utf8_helper.h>
+
+void assert_string_glyph_length_is(const char * string, int maxSize, size_t result) {
+  quiz_assert(UTF8Helper::StringGlyphLength(string, maxSize) == result);
+}
+
+QUIZ_CASE(ion_utf8_helper_glyph_length) {
+  assert_string_glyph_length_is("123", -1, 3);
+  assert_string_glyph_length_is("1ᴇ3", -1, 3);
+  assert_string_glyph_length_is("∑∫𝐢", -1, 3);
+  assert_string_glyph_length_is("123", 2, 2);
+  assert_string_glyph_length_is("1ᴇ3", 2, 1);
+}