Fixes up bash stack walking on Mac OS. There are cases where BASH_SOURCE is a sparse array with holes. This appears to be due to the sub shell launching of the tests. By using FUNCNAME as our count of stack frames, and "ignoring" the holes, we get much better stack output on the Mac. Previously we were just erroring out.

RELNOTES:none

--
MOS_MIGRATED_REVID=107255705

1 files changed, 7 insertions, 6 deletions

diff --git a/src/test/shell/unittest.bash b/src/test/shell/unittest.bash
index ace16fd4ee..0800ff32c6 100644
--- a/src/test/shell/unittest.bash
+++ b/src/test/shell/unittest.bash
@@ -215,15 +215,16 @@ __show_stack() {
     local trace_found=0
 
     # Skip over active calls within this module:
-    while [ "$i" -lt "${#BASH_SOURCE[@]}" -a "${BASH_SOURCE[$i]-}" = "${BASH_SOURCE[0]}" ]; do
-        i=$(($i + 1))
+    while (( i < ${#FUNCNAME[@]} )) && [[ ${BASH_SOURCE[i]:-} == ${BASH_SOURCE[0]} ]]; do
+       (( i++ ))
     done
 
     # Show all calls until the next one within this module (typically run_suite):
-    while [ "$i" -lt "${#BASH_SOURCE[@]}" -a "${BASH_SOURCE[$i]-}" != "${BASH_SOURCE[0]}" ]; do
-        # There's a bug in bash that explains the strange offsets.
-        echo "${BASH_SOURCE[$i]}:${BASH_LINENO[$i - 1]}: in call to ${FUNCNAME[$i - 1]}" >&2
-        i=$(($i + 1))
+    while (( i < ${#FUNCNAME[@]} )) && [[ ${BASH_SOURCE[i]:-} != ${BASH_SOURCE[0]} ]]; do
+        # Read online docs for BASH_LINENO to understand the strange offset.
+        # Undefined can occur in the BASH_SOURCE stack apparently when one exits from a subshell
+        echo "${BASH_SOURCE[i]:-"Unknown"}:${BASH_LINENO[i - 1]:-"Unknown"}: in call to ${FUNCNAME[i]:-"Unknown"}" >&2
+        (( i++ ))
         trace_found=1
     done