[COMMITTED] testsuite: fix dg-require and dg-nbd and adjust ndb tests accordingly

[Jose E. Marchesi]

FYI.

Author: Jose E. Marchesi <address@hidden>
Date:   Tue Mar 3 12:06:22 2020 +0100

    testsuite: fix dg-require and dg-nbd and adjust ndb tests accordingly
    
    This patch fixes two problems in the testsuite:
    
    1. The poke_commands variable is cleared in poke-dg-test.  However,
       this procedure is _not_ executed when a test is marked as
       UNSUPPORTED by a dg-require directive.  Consequently, spurious
       commands were being dragged from unsupported tests to the next
       test.  The solution is to make dg-command to not append to
       poke_commands if the current test is marked as UNSUPPORTED.  This
       of course requires for dg-require directives to appear before any
       dg-command directive in test files.  This is now documented in
       HACKING.
    
    2. The dg-nbd procedure was trying to implicitly dg-require nbd.  The
       arguments to dg-require were wrong (the line number argument was
       missing) and also the upvar variable wasn't referring to the global
       variable.  Also, the nbdkit command was executed regardless of the
       availability of the capability "nbd".  This patch changes dg-nbd by
       testing for the NBDKIT environment variable before trying to launch
       it.
    
    After this patch, this is what I get in a system without libnbd
    installed:
    
                    === poke Summary ===

    # of expected passes                3073
    # of unsupported tests              3
    
    Which is the expected output.
    
    2020-03-03  Jose E. Marchesi  <address@hidden>
    
            * testsuite/lib/poke-dg.exp (dg-nbd): Run nbdkit only when
            available.
            (dg-command): Do not append to poke_commands if the current test
            is being skipped as UNSUPPORTED.
            * testsuite/poke.pkl/ios-nbd-1.pk: dg-require nbd.
            * testsuite/poke.pkl/open-3.pk: Likewise.
            * testsuite/poke.cmd/nbd-1.pk: Likewise.
            * HACKING: Note that dg-require should be used before dg-command
            directives.

diff --git a/ChangeLog b/ChangeLog
index f6680d9..683384b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,15 @@
+2020-03-03  Jose E. Marchesi  <address@hidden>
+
+       * testsuite/lib/poke-dg.exp (dg-nbd): Run nbdkit only when
+       available.
+       (dg-command): Do not append to poke_commands if the current test
+       is being skipped as UNSUPPORTED.
+       * testsuite/poke.pkl/ios-nbd-1.pk: dg-require nbd.
+       * testsuite/poke.pkl/open-3.pk: Likewise.
+       * testsuite/poke.cmd/nbd-1.pk: Likewise.
+       * HACKING: Note that dg-require should be used before dg-command
+       directives.
+
 2020-03-03  Jose E. Marchesi  <address@hidden>
 
        * src/pk-utils.h (STREQ): Define.
diff --git a/HACKING b/HACKING
index facb137..3fabfbe 100644
--- a/HACKING
+++ b/HACKING
@@ -517,6 +517,9 @@ capability ``libtextstyle`` is not found in poke::
   /* { dg-command {printf "%<foo:%i32d%>", 10} } */
   /* { dg-output "<span class=\"foo\">10</span>" } */
 
+IMPORTANT NOTE: dg-require should appear before any dg-command
+directive in the test file.
+
 The supported capabilities are:
 
 libtextstyle
diff --git a/testsuite/lib/poke-dg.exp b/testsuite/lib/poke-dg.exp
index 0478c10..f7994fc 100644
--- a/testsuite/lib/poke-dg.exp
+++ b/testsuite/lib/poke-dg.exp
@@ -32,11 +32,19 @@ set poke_nbd_pids {}
 
 proc dg-command { args } {
     global poke_commands
+    upvar dg-do-what do-what
 
     if { [llength $args] > 2 } {
         error "[lindex $args 0]: too many arguments"
     }
 
+    # If this test is unsupported, then do not append anything to
+    # poke_commands.  This is needed because poke_commands doesn't get
+    # reset to {} in these cases.
+    if { [lindex ${do-what} 1] == N } {
+        return;
+    }
+
     # Prepare the command for shell unquoting.
     set cmd \"[string map \
                {$ \\$ \\ \\\\ \" \\" ` \\`} \
@@ -166,13 +174,14 @@ proc dg-nbd { args } {
     if { [llength $args] != 3 } {
         error "[lindex $args 0]: invalid arguments"
     }
-    dg-require nbd
 
-    set data [lindex $args 1]
-    set sock [lindex $args 2]
+    if { $::env(NBDKIT) != "no"} {
+        set data [lindex $args 1]
+        set sock [lindex $args 2]
 
-    set fh [open |[list nbdkit -f -U $sock data data=$data]]
-    lappend poke_nbd_pids [pid $fh]
+        set fh [open |[list nbdkit -f -U $sock data data=$data]]
+        lappend poke_nbd_pids [pid $fh]
+    }
 }
 
 # We set LC_ALL and LANG to C so that we get the same error messages
diff --git a/testsuite/poke.cmd/nbd-1.pk b/testsuite/poke.cmd/nbd-1.pk
index 0d158cb..ca70d0d 100644
--- a/testsuite/poke.cmd/nbd-1.pk
+++ b/testsuite/poke.cmd/nbd-1.pk
@@ -1,4 +1,5 @@
 /* { dg-do run } */
+/* { dg-require nbd } */
 /* { dg-nbd {0x10 0x20 0x30 0x40 0x50 0x60 0x70 0x80} [dg-tmpdir]/nbd-1 } */
 
 /* { dg-command ".nbd nbd+unix:///?socket=[dg-tmpdir]/nbd-1" } */
diff --git a/testsuite/poke.pkl/ios-nbd-1.pk b/testsuite/poke.pkl/ios-nbd-1.pk
index 4c49a77..93e979b 100644
--- a/testsuite/poke.pkl/ios-nbd-1.pk
+++ b/testsuite/poke.pkl/ios-nbd-1.pk
@@ -1,4 +1,5 @@
 /* { dg-do run } */
+/* { dg-require nbd } */
 /* { dg-nbd {0 0 0 0x10} [dg-tmpdir]/ios-nbd-1 } */
 
 /* { dg-command { .set obase 10 } } */
diff --git a/testsuite/poke.pkl/open-3.pk b/testsuite/poke.pkl/open-3.pk
index d647bbd..a8be00a 100644
--- a/testsuite/poke.pkl/open-3.pk
+++ b/testsuite/poke.pkl/open-3.pk
@@ -1,4 +1,5 @@
 /* { dg-do run } */
+/* { dg-require nbd } */
 /* { dg-nbd {0x10} [dg-tmpdir]/open-3 } */
 
 /* { dg-command { .set obase 10 } } */