kenmirrors
/
freeswitch
mirror of https://github.com/signalwire/freeswitch.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity

Fix mod_expr `clamp` function 

The clamp(v,a,b) function wraps v around the interval [a,b).

However prior to this commit, `clamp` was ignoring the third argument
and using the second argument again in its place.  This resulted in a
division by zero.  Hence `clamp` didn't work at all.

Even if the arguments were treated correctly, `clamp` incorrectly
multiplied rather than added whenever v < a.  This would have produced
bogus results.  (Thanks to Shona McNeill for pointing this out.)

Note that as implemented, `clamp` is undefined for b >= a.

These errors are present in the last upstream C version, v2.7.
They've been corrected in the C++ version that upstream now maintains
instead.

Thanks-to: Shona McNeill <prufrax@googlemail.com>

FS-7070 #resolve
This commit is contained in:
Travis Cross 2014-12-25 10:11:47 +00:00
parent d88bae1a62
commit 65e678ba1d
1 changed files with 2 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
src/mod/applications/mod_expr/exprilfs.h
View File

@ -763,7 +763,7 @@ case EXPR_NODEFUNC_CLAMP:
err = exprEvalNode(obj, nodes->data.function.nodes, 1, &d1);
if (!err)
err = exprEvalNode(obj, nodes->data.function.nodes, 1, &d2);
err = exprEvalNode(obj, nodes->data.function.nodes, 2, &d2);
if (!err) {
EXPR_RESET_ERR();
@ -771,7 +771,7 @@ case EXPR_NODEFUNC_CLAMP:
EXPR_CHECK_ERR();
if (tmp < 0.0)
*val = tmp * d2;
*val = tmp + d2;
else
*val = tmp + d1;
} else