merge trunk

2 files changed, 26 insertions, 16 deletions

diff --git a/generic/tclEnv.c b/generic/tclEnv.c
index 2cb240d..66ddb57 100644
--- a/generic/tclEnv.c
+++ b/generic/tclEnv.c
@@ -551,7 +551,8 @@ TclGetEnv(
  *	array.
  *
  * Results:
- *	Always returns NULL to indicate success.
+ *	Returns NULL to indicate success, or an error-message if the array
+ *	element being handled doesn't exist.
  *
  * Side effects:
  *	Environment variable changes get propagated. If the whole "env" array
@@ -609,8 +610,7 @@ EnvTraceProc(
 	const char *value = TclGetEnv(name2, &valueString);
 
 	if (value == NULL) {
-	    Tcl_UnsetVar2(interp, name1, name2, 0);
-	    return NULL;
+	    return (char *) "no such variable";
 	}
 	Tcl_SetVar2(interp, name1, name2, value, 0);
 	Tcl_DStringFree(&valueString);
diff --git a/tests/env.test b/tests/env.test
index 83d99e0..9f59fbc 100644
--- a/tests/env.test
+++ b/tests/env.test
@@ -278,20 +278,20 @@ test env-5.4 {corner cases - unset the env array} -setup {
 } -cleanup {
     interp delete i
 } -result {1 a 1}
-test env-5.5 {corner cases - cannot have null entries on Windows} {win} {
+test env-5.5 {corner cases - cannot have null entries on Windows} -constraints win -body {
     set env() a
     catch {set env()}
-} {1}
+} -result 1
 
-test env-6.1 {corner cases - add lots of env variables} {} {
+test env-6.1 {corner cases - add lots of env variables} -body {
     set size [array size env]
     for {set i 0} {$i < 100} {incr i} {
 	set env(BOGUS$i) $i
     }
     expr {[array size env] - $size}
-} 100
+} -result 100
 
-test env-7.1 {[219226]: whole env array should not be unset by read} {
+test env-7.1 {[219226]: whole env array should not be unset by read} -body {
     set n [array size env]
     set s [array startsearch env]
     while {[array anymore env $s]} {
@@ -300,19 +300,29 @@ test env-7.1 {[219226]: whole env array should not be unset by read} {
     }
     array donesearch env $s
     return $n
-} 0
-test env-7.2 {[219226]: links to env elements should not be removed by read} {
+} -result 0
+
+test env-7.2 {[219226]: links to env elements should not be removed by read} -body {
     apply {{} {
 	set ::env(test7_2) ok
 	upvar env(test7_2) elem
 	set ::env(PATH)
-	try {
-	    return $elem
-	} finally {
-	    unset ::env(test7_2)
-	}
+	return $elem
+    }}
+} -result ok
+
+test env-7.3 {[9b4702]: testing existence of env(some_thing) should not destroy trace} -body {
+    apply {{} {
+      catch {unset ::env(test7_3)}
+      proc foo args {
+        set ::env(test7_3) ok
+      }
+      trace add variable ::env(not_yet_existent) write foo
+      info exists ::env(not_yet_existent)
+      set ::env(not_yet_existent) "Now I'm here";
+      return [info exists ::env(test7_3)]
     }}
-} ok
+} -result 1
 
 # Restore the environment variables at the end of the test.