diff --git a/lldb/include/lldb/Utility/AnsiTerminal.h b/lldb/include/lldb/Utility/AnsiTerminal.h
index 153602cc08b09..dd2eafef1f228 100644
--- a/lldb/include/lldb/Utility/AnsiTerminal.h
+++ b/lldb/include/lldb/Utility/AnsiTerminal.h
@@ -98,6 +98,7 @@
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Support/Locale.h"
+#include "llvm/Support/Unicode.h"
 
 #include "lldb/Utility/Stream.h"
 
@@ -264,13 +265,16 @@ inline std::string TrimAndPad(llvm::StringRef str, size_t visible_length,
     // Repeatedly trim the string until it its valid unicode and fits.
     llvm::StringRef trimmed = left;
     while (!trimmed.empty()) {
-      // This relies on columnWidth returning -2 for invalid/partial unicode
-      // characters, which after conversion to size_t will be larger than the
-      // visible width.
-      column_width = llvm::sys::locale::columnWidth(trimmed);
-      if (result_visibile_length + column_width <= visible_length) {
+      int trimmed_width = llvm::sys::locale::columnWidth(trimmed);
+      if (
+          // If we have only part of a Unicode character, keep trimming.
+          trimmed_width !=
+              llvm::sys::unicode::ColumnWidthErrors::ErrorInvalidUTF8 &&
+          // If the trimmed string fits, take it.
+          result_visibile_length + static_cast<size_t>(trimmed_width) <=
+              visible_length) {
         result.append(trimmed);
-        result_visibile_length += column_width;
+        result_visibile_length += static_cast<size_t>(trimmed_width);
         break;
       }
       trimmed = trimmed.drop_back();
diff --git a/lldb/unittests/Utility/AnsiTerminalTest.cpp b/lldb/unittests/Utility/AnsiTerminalTest.cpp
index 28fa32461ad5f..8924c083a656b 100644
--- a/lldb/unittests/Utility/AnsiTerminalTest.cpp
+++ b/lldb/unittests/Utility/AnsiTerminalTest.cpp
@@ -116,6 +116,18 @@ TEST(AnsiTerminal, TrimAndPad) {
   EXPECT_EQ("    ❤️", ansi::TrimAndPad("    ❤️", 5));
   EXPECT_EQ("12❤️4❤️", ansi::TrimAndPad("12❤️4❤️", 5));
   EXPECT_EQ("12❤️45", ansi::TrimAndPad("12❤️45❤️", 5));
+
+  // This string previously triggered a bug in handling incomplete Unicode
+  // characters, when we had already accumulated some previous parts of the
+  // string.
+  const char *quick = "The \x1B[0mquick\x1B[0m 💨\x1B[0m";
+  EXPECT_EQ(ansi::TrimAndPad(quick, 0), "");
+  EXPECT_EQ(ansi::TrimAndPad(quick, 9), "The \x1B[0mquick\x1B[0m");
+  EXPECT_EQ(ansi::TrimAndPad(quick, 10), "The \x1B[0mquick\x1B[0m ");
+  // The emoji is 2 columns, so 11 is not quite enough.
+  EXPECT_EQ(ansi::TrimAndPad(quick, 11, '_'), "The \x1B[0mquick\x1B[0m _");
+  // 12 exactly enough to include the emoji and proceeding ANSI code.
+  EXPECT_EQ(ansi::TrimAndPad(quick, 12), quick);
 }
 
 static void TestLines(const std::string &input, int indent,