Improve psql's behavior when the editor is exited without saving.

When editing the previous query buffer, if the editor is exited
without modifying the temp file then clear the query buffer,
rather than re-loading (and probably re-executing) the previous
query buffer.  This reduces the probability of accidentally
re-executing something you didn't intend to.

Similarly, in "\e file", if the file isn't actually modified
then don't load it into the query buffer.  And in "\ef" and
"\ev", if no changes are made then clear the query buffer
instead of loading the function or view definition into it.

Cases where we fail to invoke the editor at all, or it returns
a nonzero status, are treated like the no-file-modification case.

Laurenz Albe, reviewed by Jacob Champion

Discussion: https://postgr.es/m/0ba3f2a658bac6546d9934ab6ba63a805d46a49b.camel@cybertec.at

1 files changed, 7 insertions, 3 deletions

diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 01ec9b8b0a6..0ba1e2d44d4 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -1970,7 +1970,9 @@ testdb=>
         </para>
 
         <para>
-        The new contents of the query buffer are then re-parsed according to
+        If you edit a file or the previous query, and you quit the editor without
+        modifying the file, the query buffer is cleared.
+        Otherwise, the new contents of the query buffer are re-parsed according to
         the normal rules of <application>psql</application>, treating the
         whole buffer as a single line.  Any complete queries are immediately
         executed; that is, if the query buffer contains or ends with a
@@ -2039,7 +2041,8 @@ Tue Oct 26 21:40:57 CEST 1999
          in the form of a <command>CREATE OR REPLACE FUNCTION</command> or
          <command>CREATE OR REPLACE PROCEDURE</command> command.
          Editing is done in the same way as for <literal>\edit</literal>.
-         After the editor exits, the updated command is executed immediately
+         If you quit the editor without saving, the statement is discarded.
+         If you save and exit the editor, the updated command is executed immediately
          if you added a semicolon to it.  Otherwise it is redisplayed;
          type semicolon or <literal>\g</literal> to send it, or <literal>\r</literal>
          to cancel.
@@ -2115,7 +2118,8 @@ Tue Oct 26 21:40:57 CEST 1999
          This command fetches and edits the definition of the named view,
          in the form of a <command>CREATE OR REPLACE VIEW</command> command.
          Editing is done in the same way as for <literal>\edit</literal>.
-         After the editor exits, the updated command is executed immediately
+         If you quit the editor without saving, the statement is discarded.
+         If you save and exit the editor, the updated command is executed immediately
          if you added a semicolon to it.  Otherwise it is redisplayed;
          type semicolon or <literal>\g</literal> to send it, or <literal>\r</literal>
          to cancel.