Add support for history --merge to incorporate history changes from

other sessions.

Fixes #825

1 files changed, 5 insertions, 2 deletions

diff --git a/history.h b/history.h
index e6d48682..5b7292e8 100644
--- a/history.h
+++ b/history.h
@@ -154,8 +154,8 @@ private:
     /** The file ID of the file we mmap'd */
     file_id_t mmap_file_id;
 
-    /** Timestamp of when this history was created */
-    const time_t birth_timestamp;
+    /** The boundary timestamp distinguishes old items from new items. Items whose timestamps are <= the boundary are considered "old". Items whose timestemps are > the boundary are new, and are ignored by this instance (unless they came from this instance). The timestamp may be adjusted by incorporate_external_changes() */
+    time_t boundary_timestamp;
 
     /** How many items we add until the next vacuum. Initially a random value. */
     int countdown_to_vacuum;
@@ -233,6 +233,9 @@ public:
     /** Populates from a bash history file */
     void populate_from_bash(FILE *f);
 
+    /** Incorporates the history of other shells into this history */
+    void incorporate_external_changes();
+
     /* Gets all the history into a string with ARRAY_SEP_STR. This is intended for the $history environment variable. This may be long! */
     void get_string_representation(wcstring &str, const wcstring &separator);