Clearly document behaviour when end of file is reached.
Closes #260.
diff --git a/man/zip_fread.mdoc b/man/zip_fread.mdoc
index 4d3e8d6..48166b7 100644
--- a/man/zip_fread.mdoc
+++ b/man/zip_fread.mdoc
@@ -29,7 +29,7 @@
.\" OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
.\" IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
.\"
-.Dd December 18, 2017
+.Dd September 28, 2021
.Dt ZIP_FREAD 3
.Os
.Sh NAME
@@ -44,7 +44,7 @@
.Sh DESCRIPTION
The
.Fn zip_fread
-function reads at most
+function reads up to
.Ar nbytes
bytes from
.Ar file
@@ -52,7 +52,10 @@
.Ar buf .
.Sh RETURN VALUES
If successful, the number of bytes actually read is returned.
-Otherwise, \-1 is returned.
+When
+.Fn zip_fread
+is called after reaching the end of the file, 0 is returned.
+In case of error, \-1 is returned.
.Sh SEE ALSO
.Xr libzip 3 ,
.Xr zip_fclose 3 ,
diff --git a/man/zip_source_read.mdoc b/man/zip_source_read.mdoc
index 1e7bc02..c0fa37d 100644
--- a/man/zip_source_read.mdoc
+++ b/man/zip_source_read.mdoc
@@ -29,7 +29,7 @@
.\" OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
.\" IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
.\"
-.Dd December 18, 2017
+.Dd September 28, 2021
.Dt ZIP_SOURCE_READ 3
.Os
.Sh NAME
@@ -58,7 +58,9 @@
first.
.Sh RETURN VALUES
Upon successful completion the number of bytes read is returned.
-Upon reading end-of-file, zero is returned.
+When
+.Fn zip_source_read
+is called after reaching the end of the file, 0 is returned.
Otherwise, \-1 is returned and the error information in
.Ar source
is set to indicate the error.
