Disallow recursive xtrace (#46095)
yash/trunk/NEWS (diff) yash/trunk/NEWS.ja (diff)
yash/trunk/exec.c (diff) yash/trunk/tests/option-y.tst (diff)| @@ -23,6 +23,8 @@ | ||
| 23 | 23 | = The "array" built-in is now completely ignored in the POSIXly- |
| 24 | 24 | correct mode. The built-in, formerly a regular built-in, is now |
| 25 | 25 | categorized as an "extension" built-in. |
| 26 | + = The xtrace option is now ignored while expanding the $PS4 | |
| 27 | + variable to prevent possible infinite recursion. | |
| 26 | 28 | * The allexport option was wrongly ignored in many assignment |
| 27 | 29 | contexts. |
| 28 | 30 | * The errexit and errreturn options now work for assignment error |
| @@ -822,10 +822,12 @@ | ||
| 822 | 822 | /* Prints a trace if the "xtrace" option is on. */ |
| 823 | 823 | void print_xtrace(void *const *argv) |
| 824 | 824 | { |
| 825 | + static bool expanding_ps4 = false; | |
| 826 | + | |
| 825 | 827 | bool tracevars = xtrace_buffer.contents != NULL |
| 826 | 828 | && xtrace_buffer.length > 0; |
| 827 | 829 | |
| 828 | - if (shopt_xtrace | |
| 830 | + if (shopt_xtrace && !expanding_ps4 | |
| 829 | 831 | && (!is_executing_auxiliary || shopt_traceall) |
| 830 | 832 | && (tracevars || argv != NULL) |
| 831 | 833 | #if YASH_ENABLE_LINEEDIT |
| @@ -834,7 +836,12 @@ | ||
| 834 | 836 | ) { |
| 835 | 837 | bool first = true; |
| 836 | 838 | |
| 839 | + // Disallow recursion in case $PS4 contains a command substitution | |
| 840 | + // that may trigger another xtrace, which would be an infinite loop | |
| 841 | + expanding_ps4 = true; | |
| 837 | 842 | struct promptset_T prompt = get_prompt(4); |
| 843 | + expanding_ps4 = false; | |
| 844 | + | |
| 838 | 845 | print_prompt(prompt.main); |
| 839 | 846 | print_prompt(prompt.styler); |
| 840 | 847 |
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