Descriptor values were quoted twice.

src/interfaces/ecpg/ChangeLog

src/interfaces/ecpg/ecpglib/execute.c

src/interfaces/ecpg/test/expected/pgtypeslib-dt_test.c

src/interfaces/ecpg/test/expected/pgtypeslib-dt_test.stderr

src/interfaces/ecpg/test/expected/sql-desc.c

src/interfaces/ecpg/test/expected/sql-desc.stderr

src/interfaces/ecpg/test/expected/sql-desc.stdout

src/interfaces/ecpg/test/pgtypeslib/dt_test.pgc

src/interfaces/ecpg/test/sql/desc.pgc