Fix potential buffer overrun in error module.

errorInternalThrow() called strncpy(stackTraceBuffer, stackTrace, n - 1) followed by messageBuffer[n - 1] = '\0' -- a copy-paste bug that wrote the NUL terminator into the wrong buffer.

Since both buffers are ERROR_MESSAGE_BUFFER_SIZE the errant write was in-bounds and messageBuffer was already terminated, so the bug was silent in practice. But when stackTrace's length >= sizeof(stackTraceBuffer) - 1, strncpy() does not null-terminate, leaving stackTraceBuffer non-terminated and exposing errorContext.error.stackTrace to over-read by any consumer.

doc/xml/release/2020s/2026/2.59.0.xml

@@ -1,5 +1,16 @@
 <release date="XXXX-XX-XX" version="2.59.0dev" title="UNDER DEVELOPMENT">
     <release-core-list>
+        <release-bug-list>
+            <release-item>
+                <release-item-contributor-list>
+                    <release-item-contributor id="christophe.pettus"/>
+                    <release-item-reviewer id="david.steele"/>
+                </release-item-contributor-list>
+
+                <p>Fix potential buffer overrun in error module.</p>
+            </release-item>
+        </release-bug-list>
+
         <release-feature-list>
             <release-item>
                 <github-pull-request id="2779"/>

src/common/error/error.c

@@ -387,8 +387,9 @@ errorInternalThrow(
     // If a stack trace was provided
     if (stackTrace != NULL)
     {
+        // strncpy() does not null-terminate when the source length >= size, so force termination on stackTraceBuffer
         strncpy(stackTraceBuffer, stackTrace, sizeof(stackTraceBuffer) - 1);
-        messageBuffer[sizeof(stackTraceBuffer) - 1] = '\0';
+        stackTraceBuffer[sizeof(stackTraceBuffer) - 1] = '\0';
     }
     // Else generate the stack trace for the error
     else if (