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Author: nyalldawson

python/core/processing/qgsprocessingutils.sip

@@ -199,6 +199,12 @@ class QgsProcessingUtils
 
  Duplicate field names will be altered to "name_2", "name_3", etc, finding the first
  non-duplicate name.
+
+.. note::
+
+   Some output file formats (e.g. shapefiles) have restrictions on the maximum
+ length of field names, so be aware that the results of calling this method may
+ be truncated when saving to these formats.
  :rtype: QgsFields
 %End
 

src/core/processing/qgsprocessingutils.h

@@ -229,6 +229,10 @@ class CORE_EXPORT QgsProcessingUtils
      *
      * Duplicate field names will be altered to "name_2", "name_3", etc, finding the first
      * non-duplicate name.
+     *
+     * \note Some output file formats (e.g. shapefiles) have restrictions on the maximum
+     * length of field names, so be aware that the results of calling this method may
+     * be truncated when saving to these formats.
      */
     static QgsFields combineFields( const QgsFields &fieldsA, const QgsFields &fieldsB );