core: fix partial completion when the common prefix found is empty (closes #340)

ChangeLog.adoc

@@ -55,6 +55,7 @@ New features::
 Bug fixes::
 
   * core: fix completion after newline in input (issue #1925)
+  * core: fix partial completion when the common prefix found is empty (issue #340)
   * core: display a specific error when trying to bind a key without area in mouse context
   * core: fix display of key with command `/key bindctxt <context> <key>`
   * core: fix default value of bar options (issue #846)

src/gui/gui-input.c

@@ -416,6 +416,14 @@ gui_input_complete (struct t_gui_buffer *buffer)
     if (!buffer->completion || !buffer->completion->word_found)
         return;
 
+    /*
+     * in case the word found is empty, we keep the word in input as-is
+     * (this can happen with partial completion when the common prefix found
+     * is empty)
+     */
+    if (!buffer->completion->word_found[0])
+        return;
+
     /* replace word with new completed word into input buffer */
     if (buffer->completion->diff_size > 0)
     {