[main] --eval flag respects errexit

Author: Andy C

core/shell.py

@@ -974,8 +974,8 @@ def Main(
         if not ok:
             return 1
 
-        # Runtime error
-        if status != 0:
+        # YSH will stop on errors.  OSH keep going, a bit like 'source'.
+        if status != 0 and exec_opts.errexit():
             return status
 
     #

doc/ref/chap-front-end.md

@@ -106,16 +106,16 @@ They also accept these flags:
     -n                Parse the program but don't execute it.  Print the AST.
     --ast-format FMT  The format for the AST (text|text-abbrev)
     --eval FILE       Evaluate the given file, similar to the 'source' builtin.
-                      Specify it multiple times to run multiple files.  The
-                      shell stops on normal errors, as well as when $? is
-                      non-zero after evaluating a file (even if errexit is
-                      off).
+                      Specify it multiple times to run multiple files.  If the
+                      errexit option is on (e.g. in YSH), then the shell stops
+                      when $? is non-zero after evaluating a file.
     --tool            Run a tool instead of the shell (cat-em|syntax-tree)
 
 Examples:
 
-    osh -n -c 'hello'                    # pretty-print the AST
-    ysh --ast-format text -n -c 'hello'  # print it full
+    ysh --eval one.ysh --eval two.ysh -c 'echo hi'  # Run 2 files first
+    osh -n -c 'hello'                               # pretty-print the AST
+    ysh --ast-format text -n -c 'hello'             # in unabridged format
 ```
 
 <h3 id="config" class="osh-ysh-topic">config</h3>

spec/sh-usage.test.sh

@@ -100,23 +100,24 @@ echo 'echo one "$@"' > one.sh
 echo 'echo fail "$@"; ( exit 42 )' > fail.sh
 
 $SH --eval one.sh \
-  -c 'echo flag -c "$@"' dummy x y z
+  -c 'echo status=$? flag -c "$@"' dummy x y z
 echo
 
 # Even though errexit is off, the shell exits if the last status of an --eval
 # file was non-zero.
 
 $SH --eval one.sh --eval fail.sh \
-  -c 'echo flag -c "$@"' dummy x y z
+  -c 'echo status=$? flag -c "$@"' dummy x y z
 echo status=$?
 
 ## STDOUT:
 one x y z
-flag -c x y z
+status=0 flag -c x y z
 
 one x y z
 fail x y z
-status=42
+status=42 flag -c x y z
+status=0
 ## END
 
 ## N-I bash/dash/mksh/zsh STDOUT: