--- /dev/null
+ BASH PATCH REPORT
+ =================
+
+Bash-Release: 5.0
+Patch-ID: bash50-010
+
+Bug-Reported-by: Thorsten Glaser <tg@mirbsd.de>
+Bug-Reference-ID: <156622962831.19438.16374961114836556294.reportbug@tglase.lan.tarent.de>
+Bug-Reference-URL: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=935115
+
+Bug-Description:
+
+Bash-5.0 changed the way assignment statements preceding special builtins
+and shell functions were handled in posix mode. They automatically created
+or modified global variables instead of modifying existing local variables
+as in bash-4.4.
+
+The bash-4.4 posix-mode semantics were buggy, and resulted in creating
+local variables where they were not intended and modifying global variables
+and local variables simultaneously.
+
+The bash-5.0 changes were intended to fix this issue, but did not preserve
+enough backwards compatibility. The posix standard also changed what it
+required in these cases, so bash-5.0 is not bound by the strict conformance
+requirements that existed in previous issues of the standard.
+
+This patch modifies the bash-5.0 posix mode behavior in an effort to restore
+some backwards compatibility and rationalize the behavior in the presence of
+local variables. It
+
+1. Changes the assignment semantics to be more similar to standalone assignment
+ statements: assignments preceding a function call or special builtin while
+ executing in a shell function will modify the value of a local variable
+ with the same name for the duration of the function's execution;
+
+2. Changes assignments preceding shell function calls or special builtins
+ from within a shell function to no longer create or modify global variables
+ in the presence of a local variable with the same name;
+
+3. Assignment statements preceding a shell function call or special builtin
+ at the global scope continue to modify the (global) calling environment,
+ but are unaffected by assignments preceding function calls or special
+ builtins within a function, as described in item 2. This is also similar
+ to the behavior of a standalone assignment statement.
+
+Patch (apply with `patch -p0'):
+
+*** ../bash-5.0-patched/variables.c 2018-12-18 11:07:21.000000000 -0500
+--- variables.c 2019-08-22 10:53:44.000000000 -0400
+***************
+*** 4461,4467 ****
+
+ /* Take a variable from an assignment statement preceding a posix special
+! builtin (including `return') and create a global variable from it. This
+! is called from merge_temporary_env, which is only called when in posix
+! mode. */
+ static void
+ push_posix_temp_var (data)
+--- 4461,4467 ----
+
+ /* Take a variable from an assignment statement preceding a posix special
+! builtin (including `return') and create a variable from it as if a
+! standalone assignment statement had been performed. This is called from
+! merge_temporary_env, which is only called when in posix mode. */
+ static void
+ push_posix_temp_var (data)
+***************
+*** 4473,4486 ****
+ var = (SHELL_VAR *)data;
+
+! binding_table = global_variables->table;
+! if (binding_table == 0)
+! binding_table = global_variables->table = hash_create (VARIABLES_HASH_BUCKETS);
+!
+! v = bind_variable_internal (var->name, value_cell (var), binding_table, 0, ASS_FORCE|ASS_NOLONGJMP);
+
+ /* global variables are no longer temporary and don't need propagating. */
+! var->attributes &= ~(att_tempvar|att_propagate);
+ if (v)
+! v->attributes |= var->attributes;
+
+ if (find_special_var (var->name) >= 0)
+--- 4473,4497 ----
+ var = (SHELL_VAR *)data;
+
+! /* Just like do_assignment_internal(). This makes assignments preceding
+! special builtins act like standalone assignment statements when in
+! posix mode, satisfying the posix requirement that this affect the
+! "current execution environment." */
+! v = bind_variable (var->name, value_cell (var), ASS_FORCE|ASS_NOLONGJMP);
+!
+! /* If this modifies an existing local variable, v->context will be non-zero.
+! If it comes back with v->context == 0, we bound at the global context.
+! Set binding_table appropriately. It doesn't matter whether it's correct
+! if the variable is local, only that it's not global_variables->table */
+! binding_table = v->context ? shell_variables->table : global_variables->table;
+
+ /* global variables are no longer temporary and don't need propagating. */
+! if (binding_table == global_variables->table)
+! var->attributes &= ~(att_tempvar|att_propagate);
+!
+ if (v)
+! {
+! v->attributes |= var->attributes;
+! v->attributes &= ~att_tempvar; /* not a temp var now */
+! }
+
+ if (find_special_var (var->name) >= 0)
+***************
+*** 4576,4587 ****
+ {
+ int i;
+
+ tempvar_list = strvec_create (HASH_ENTRIES (temporary_env) + 1);
+ tempvar_list[tvlist_ind = 0] = 0;
+!
+! hash_flush (temporary_env, pushf);
+! hash_dispose (temporary_env);
+ temporary_env = (HASH_TABLE *)NULL;
+
+ tempvar_list[tvlist_ind] = 0;
+
+--- 4587,4601 ----
+ {
+ int i;
++ HASH_TABLE *disposer;
+
+ tempvar_list = strvec_create (HASH_ENTRIES (temporary_env) + 1);
+ tempvar_list[tvlist_ind = 0] = 0;
+!
+! disposer = temporary_env;
+ temporary_env = (HASH_TABLE *)NULL;
+
++ hash_flush (disposer, pushf);
++ hash_dispose (disposer);
++
+ tempvar_list[tvlist_ind] = 0;
+
+*** ../bash-5.0-patched/tests/varenv.right 2018-12-17 15:39:48.000000000 -0500
+--- tests/varenv.right 2019-08-22 16:05:25.000000000 -0400
+***************
+*** 147,153 ****
+ outside: declare -- var="one"
+ inside: declare -x var="value"
+! outside: declare -x var="value"
+! inside: declare -- var="local"
+! outside: declare -x var="global"
+ foo=<unset> environment foo=
+ foo=foo environment foo=foo
+--- 147,153 ----
+ outside: declare -- var="one"
+ inside: declare -x var="value"
+! outside: declare -- var="outside"
+! inside: declare -x var="global"
+! outside: declare -- var="outside"
+ foo=<unset> environment foo=
+ foo=foo environment foo=foo
+*** ../bash-5.0/patchlevel.h 2016-06-22 14:51:03.000000000 -0400
+--- patchlevel.h 2016-10-01 11:01:28.000000000 -0400
+***************
+*** 26,30 ****
+ looks for to find the patch level (for the sccs version string). */
+
+! #define PATCHLEVEL 9
+
+ #endif /* _PATCHLEVEL_H_ */
+--- 26,30 ----
+ looks for to find the patch level (for the sccs version string). */
+
+! #define PATCHLEVEL 10
+
+ #endif /* _PATCHLEVEL_H_ */
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