48147/0002: zmathfunc: Fix bug where the exit code would be non-zero if the expression evaluted to zero.

3 files changed, 13 insertions, 3 deletions

diff --git a/ChangeLog b/ChangeLog
index d77fb2df5..022e38994 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,9 @@
 2021-03-07  Daniel Shahaf  <d.s@daniel.shahaf.name>
 
+	* 48147/0002: Functions/Math/zmathfunc, Test/Z02zmathfunc.ztst:
+	zmathfunc: Fix bug where the exit code would be non-zero if
+	the expression evaluted to zero.
+
 	* 48147/0001: Test/Z02zmathfunc.ztst: tests: Add a unit test for
 	zmathfunc and a regression test for workers/48146 affecting it.
 
diff --git a/Functions/Math/zmathfunc b/Functions/Math/zmathfunc
index 4ff40700d..8e4b78549 100644
--- a/Functions/Math/zmathfunc
+++ b/Functions/Math/zmathfunc
@@ -1,34 +1,40 @@
 #autoload
 
 zsh_math_func_min() {
+  emulate -L zsh
   local result=$1
   shift
   local arg
   for arg ; do
     (( $arg < result )) && result=$arg
   done
-  (( result )) # return
+  (( result ))
+  true # Careful here: `return 0` evaluates an arithmetic expression
 }
 functions -M min 1 -1 zsh_math_func_min # at least one argument
 
 zsh_math_func_max() {
+  emulate -L zsh
   local result=$1
   shift
   local arg
   for arg ; do
     (( $arg > result )) && result=$arg
   done
-  (( result )) # return
+  (( result ))
+  true # Careful here: `return 0` evaluates an arithmetic expression
 }
 functions -M max 1 -1 zsh_math_func_max # at least one argument
 
 zsh_math_func_sum() {
+  emulate -L zsh
   local sum
   local arg
   for arg ; do
     (( sum += $arg ))
   done
   (( sum ))
+  true # Careful here: `return 0` evaluates an arithmetic expression
 }
 functions -M sum 0 -1 zsh_math_func_sum
 
diff --git a/Test/Z02zmathfunc.ztst b/Test/Z02zmathfunc.ztst
index 94bc59576..43a0a0d76 100644
--- a/Test/Z02zmathfunc.ztst
+++ b/Test/Z02zmathfunc.ztst
@@ -15,7 +15,7 @@
   (set -e; echo $(( min(0,   42) )))
   (set -e; echo $(( max(0,  -42) )))
   (set -e; echo $(( sum(42, -42) )))
--f:regression test for ERR_EXIT 
+0:regression test for ERR_EXIT 
 >0
 >0
 >0