--- a/layout/reftests/svg/text/reftest.list
+++ b/layout/reftests/svg/text/reftest.list
@@ -109,16 +109,17 @@ fails-if(geckoview) == multiple-chunks-m
 == simple-multiline-number.svg simple-multiline-number-ref.svg
 == simple-multiline-pc.svg simple-multiline-pc-ref.svg
 == simple-multiline-anchor-end.svg simple-multiline-anchor-end-ref.svg
 
 random-if(/^Windows\x20NT\x206\.1/.test(http.oscpu)) fuzzy-if(skiaContent,0-1,0-15) == textpath.svg textpath-ref.svg # Bug 1392106
 random-if(/^Windows\x20NT\x206\.1/.test(http.oscpu)) == textpath-a.svg textpath-a-ref.svg # Bug 1392106
 random-if(/^Windows\x20NT\x206\.1/.test(http.oscpu)) == textpath-anchor-middle.svg textpath-anchor-middle-ref.svg # Bug 1392106
 random-if(/^Windows\x20NT\x206\.1/.test(http.oscpu)) == textpath-anchor-end.svg textpath-anchor-end-ref.svg # Bug 1392106
+random-if(/^Windows\x20NT\x206\.1/.test(http.oscpu)) == textpath-cluster.svg textpath-cluster-ref.svg # Bug 1392106
 random-if(/^Windows\x20NT\x206\.1/.test(http.oscpu)) == textpath-invalid-parent.svg textpath-invalid-parent-ref.svg # Bug 1392106
 random-if(/^Windows\x20NT\x206\.1/.test(http.oscpu)) == textpath-multiline.svg textpath-multiline-ref.svg # Bug 1392106
 random-if(/^Windows\x20NT\x206\.1/.test(http.oscpu)) == textpath-multiline-2.svg textpath-multiline-2-ref.svg # Bug 1392106
 random-if(/^Windows\x20NT\x206\.1/.test(http.oscpu)) == textpath-after.svg textpath-after-ref.svg # Bug 1392106
 random-if(/^Windows\x20NT\x206\.1/.test(http.oscpu)) == textpath-after-anchor-end.svg textpath-after-anchor-end-ref.svg # Bug 1392106
 random-if(/^Windows\x20NT\x206\.1/.test(http.oscpu)) == textpath-reset-position.svg textpath-reset-position-ref.svg # Bug 1392106
 random-if(/^Windows\x20NT\x206\.1/.test(http.oscpu)) == textpath-inherit-position.svg textpath-inherit-position-ref.svg # Bug 1392106
 

new file mode 100644
--- /dev/null
+++ b/layout/reftests/svg/text/textpath-cluster-ref.svg
@@ -0,0 +1,12 @@
+<svg width="500" height="500" xmlns="http://www.w3.org/2000/svg" >
+  <defs>
+    <path id="path" d="M 100 200 C 200 100 300 0 400 100" />
+    <style>
+      text {
+        font: 40px monospace;
+      }
+    </style>
+  </defs>
+
+  <text transform="translate(0, 40)">a <textPath href="#path">b </textPath>c</text>
+</svg>

new file mode 100644
--- /dev/null
+++ b/layout/reftests/svg/text/textpath-cluster.svg
@@ -0,0 +1,12 @@
+<svg width="500" height="500" xmlns="http://www.w3.org/2000/svg" >
+  <defs>
+    <path id="path" d="M 100 200 C 200 100 300 0 400 100" />
+    <style>
+      text {
+        font: 40px monospace;
+      }
+    </style>
+  </defs>
+
+  <text transform="translate(0, 40)">a <textPath href="#path">b </textPath> c</text>
+</svg>

--- a/layout/svg/SVGTextFrame.cpp
+++ b/layout/svg/SVGTextFrame.cpp
@@ -4655,19 +4655,20 @@ void SVGTextFrame::DoTextPathLayout() {
         continue;
       }
       if (it.IsClusterAndLigatureGroupStart()) {
         break;
       }
       it.Next();
     }
 
+    bool skippedEndOfTextPath = false;
+
     // Loop for each character in the text path.
-    while (!it.AtEnd() && it.TextPathFrame() &&
-           it.TextPathFrame()->GetContent() == textPath) {
+    while (!it.AtEnd() && it.TextPathFrame()) {
       // The index of the cluster or ligature group's first character.
       uint32_t i = it.TextElementCharIndex();
 
       // The index of the next character of the cluster or ligature.
       // We track this as we loop over the characters below so that we
       // can detect undisplayed characters and append entries into
       // partialAdvances for them.
       uint32_t j = i + 1;
@@ -4690,24 +4691,31 @@ void SVGTextFrame::DoTextPathLayout() {
           partialAdvances.AppendElement(partialAdvance);
           ++j;
         }
         // This loop may end up outside of the current text path, but
         // that's OK; we'll consider any complete cluster or ligature
         // group that begins inside the text path as being affected
         // by it.
         if (it.IsOriginalCharSkipped()) {
+          if (!it.TextPathFrame()) {
+            skippedEndOfTextPath = true;
+            break;
+          }
           // Leave partialAdvance unchanged.
         } else if (it.IsClusterAndLigatureGroupStart()) {
           break;
         } else {
           partialAdvance += it.GetAdvance(context);
         }
         partialAdvances.AppendElement(partialAdvance);
       }
+      if (skippedEndOfTextPath) {
+        break;
+      }
 
       // Any final undisplayed characters the CharIterator skipped over.
       MOZ_ASSERT(j <= it.TextElementCharIndex());
       while (j < it.TextElementCharIndex()) {
         partialAdvances.AppendElement(partialAdvance);
         ++j;
       }