test: Bump expect's match_max to 20000 by default

Some of our tests result in quite a bit of output (more than the expect
default of 2000 bytes), and we may not have no good, generally applicable
way to reduce it in all cases.

Author: scop

test/lib/library.exp

@@ -1043,10 +1043,11 @@ proc start_interactive_test {} {
         init_bash_xtrace
     }
     global OPT_BUFFER_SIZE
-    if {[info exists OPT_BUFFER_SIZE]} {
-        verbose "Changing default expect match buffer size to $OPT_BUFFER_SIZE"
-        match_max $OPT_BUFFER_SIZE
+    if {![info exists OPT_BUFFER_SIZE]} {
+        set OPT_BUFFER_SIZE 20000
     }
+    verbose "Changing default expect match buffer size to $OPT_BUFFER_SIZE"
+    match_max $OPT_BUFFER_SIZE
     global OPT_TIMEOUT
     if {[info exists OPT_TIMEOUT]} {
         global timeout

test/run

@@ -10,7 +10,7 @@ usage() {
     echo
     echo "Interesting options:"
     echo "  --tool_exec=    Test against a different bash executable."
-    echo "  --buffer_size   Change expect match buffer size from the default of 2000 bytes."
+    echo "  --buffer_size   Change expect match buffer size from our default of 20000 bytes."
     echo "  --debug         Create a dbg.log in the test directory with detailed expect match information."
     echo "  --timeout       Change expect timeout from the default of 10 seconds."
     echo "  --debug-xtrace  Create an xtrace.log in the test directory with set -x output."