ash: retain envvars with bad names in initial environment. Closes 10231

Reworks "ash: [VAR] Sanitise environment variable names on entry"
commit.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 22 insertions, 4 deletions

diff --git a/shell/ash.c b/shell/ash.c
index 88e607f08..7a0b88c68 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -10863,9 +10863,17 @@ showvars(const char *sep_prefix, int on, int off)
                 const char *p;
                 const char *q;
 
-                p = strchrnul(*ep, '=');
+                p = endofname(*ep);
+/* Used to have simple "p = strchrnul(*ep, '=')" here instead, but this
+ * makes "export -p" to have output not suitable for "eval":
+ * import os
+ * os.environ["test-test"]="test"
+ * if os.fork() == 0:
+ *   os.execv("ash", [ 'ash', '-c', 'eval $(export -p); echo OK' ])  # fixes this
+ * os.execv("ash", [ 'ash', '-c', 'env | grep test-test' ])
+ */
                 q = nullstr;
-                if (*p)
+                if (*p == '=')
                         q = single_quote(++p);
                 out1fmt("%s%s%.*s%s\n", sep_prefix, sep, (int)(p - *ep), *ep, q);
         }
@@ -13639,8 +13647,18 @@ init(void)
 
                 initvar();
                 for (envp = environ; envp && *envp; envp++) {
-                        p = endofname(*envp);
-                        if (p != *envp && *p == '=') {
+/* Used to have
+ *                      p = endofname(*envp);
+ *                      if (p != *envp && *p == '=') {
+ * here to weed out badly-named variables, but this breaks
+ * scenarios where people do want them passed to children:
+ * import os
+ * os.environ["test-test"]="test"
+ * if os.fork() == 0:
+ *   os.execv("ash", [ 'ash', '-c', 'eval $(export -p); echo OK' ])  # fixes this
+ * os.execv("ash", [ 'ash', '-c', 'env | grep test-test' ])  # breaks this
+ */
+                        if (strchr(*envp, '=')) {
                                 setvareq(*envp, VEXPORT|VTEXTFIXED);
                         }
                 }