patch 8.2.5146: memory leak when substitute expression nests
Problem: Memory leak when substitute expression nests.
Solution: Use an array of expression results.
diff --git a/src/regexp.c b/src/regexp.c
index 3c1334d..e6b75ea 100644
--- a/src/regexp.c
+++ b/src/regexp.c
@@ -1922,6 +1922,23 @@
return result;
}
+#if defined(FEAT_EVAL) || defined(PROTO)
+// When nesting more than a couple levels it's probably a mistake.
+# define MAX_REGSUB_NESTING 4
+static char_u *eval_result[MAX_REGSUB_NESTING] = {NULL, NULL, NULL, NULL};
+
+# if defined(EXITFREE) || defined(PROTO)
+ void
+free_resub_eval_result(void)
+{
+ int i;
+
+ for (i = 0; i < MAX_REGSUB_NESTING; ++i)
+ VIM_CLEAR(eval_result[i]);
+}
+# endif
+#endif
+
static int
vim_regsub_both(
char_u *source,
@@ -1941,7 +1958,8 @@
linenr_T clnum = 0; // init for GCC
int len = 0; // init for GCC
#ifdef FEAT_EVAL
- static char_u *eval_result = NULL;
+ static int nesting = 0;
+ int nested;
#endif
int copy = flags & REGSUB_COPY;
@@ -1953,6 +1971,14 @@
}
if (prog_magic_wrong())
return 0;
+#ifdef FEAT_EVAL
+ if (nesting == MAX_REGSUB_NESTING)
+ {
+ emsg(_(e_substitute_nesting_too_deep));
+ return 0;
+ }
+ nested = nesting;
+#endif
src = source;
dst = dest;
@@ -1969,11 +1995,11 @@
// "flags & REGSUB_COPY" != 0.
if (copy)
{
- if (eval_result != NULL)
+ if (eval_result[nested] != NULL)
{
- STRCPY(dest, eval_result);
- dst += STRLEN(eval_result);
- VIM_CLEAR(eval_result);
+ STRCPY(dest, eval_result[nested]);
+ dst += STRLEN(eval_result[nested]);
+ VIM_CLEAR(eval_result[nested]);
}
}
else
@@ -1981,7 +2007,7 @@
int prev_can_f_submatch = can_f_submatch;
regsubmatch_T rsm_save;
- VIM_CLEAR(eval_result);
+ VIM_CLEAR(eval_result[nested]);
// The expression may contain substitute(), which calls us
// recursively. Make sure submatch() gets the text from the first
@@ -1995,6 +2021,11 @@
rsm.sm_maxline = rex.reg_maxline;
rsm.sm_line_lbr = rex.reg_line_lbr;
+ // Although unlikely, it is possible that the expression invokes a
+ // substitute command (it might fail, but still). Therefore keep
+ // an array if eval results.
+ ++nesting;
+
if (expr != NULL)
{
typval_T argv[2];
@@ -2034,26 +2065,27 @@
if (rettv.v_type == VAR_UNKNOWN)
// something failed, no need to report another error
- eval_result = NULL;
+ eval_result[nested] = NULL;
else
{
- eval_result = tv_get_string_buf_chk(&rettv, buf);
- if (eval_result != NULL)
- eval_result = vim_strsave(eval_result);
+ eval_result[nested] = tv_get_string_buf_chk(&rettv, buf);
+ if (eval_result[nested] != NULL)
+ eval_result[nested] = vim_strsave(eval_result[nested]);
}
clear_tv(&rettv);
}
else if (substitute_instr != NULL)
// Execute instructions from ISN_SUBSTITUTE.
- eval_result = exe_substitute_instr();
+ eval_result[nested] = exe_substitute_instr();
else
- eval_result = eval_to_string(source + 2, TRUE);
+ eval_result[nested] = eval_to_string(source + 2, TRUE);
+ --nesting;
- if (eval_result != NULL)
+ if (eval_result[nested] != NULL)
{
int had_backslash = FALSE;
- for (s = eval_result; *s != NUL; MB_PTR_ADV(s))
+ for (s = eval_result[nested]; *s != NUL; MB_PTR_ADV(s))
{
// Change NL to CR, so that it becomes a line break,
// unless called from vim_regexec_nl().
@@ -2077,15 +2109,15 @@
if (had_backslash && (flags & REGSUB_BACKSLASH))
{
// Backslashes will be consumed, need to double them.
- s = vim_strsave_escaped(eval_result, (char_u *)"\\");
+ s = vim_strsave_escaped(eval_result[nested], (char_u *)"\\");
if (s != NULL)
{
- vim_free(eval_result);
- eval_result = s;
+ vim_free(eval_result[nested]);
+ eval_result[nested] = s;
}
}
- dst += STRLEN(eval_result);
+ dst += STRLEN(eval_result[nested]);
}
can_f_submatch = prev_can_f_submatch;