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| author | Kristian Evers <kristianevers@gmail.com> | 2017-05-23 17:37:42 +0200 |
|---|---|---|
| committer | Kristian Evers <kristianevers@gmail.com> | 2017-05-23 21:07:02 +0200 |
| commit | a54611f16cf2140d93f8a33563bbc79af136636a (patch) | |
| tree | 32f2962f8c042ab89734e18c8a7a3d4b5f35828a /src | |
| parent | 8110056d51ff94f4bc545a10306915f442cdc839 (diff) | |
| download | PROJ-a54611f16cf2140d93f8a33563bbc79af136636a.tar.gz PROJ-a54611f16cf2140d93f8a33563bbc79af136636a.zip | |
Fix possible zero division.
For some extreme values of eccentricity a zero divison can occur. In
those rare cases we return HUGE_VAL to indicate something went wrong
while still returning a defined value.
Credit to OSS Fuzz.
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=1801
Diffstat (limited to 'src')
| -rw-r--r-- | src/pj_tsfn.c | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/src/pj_tsfn.c b/src/pj_tsfn.c index 448aae99..eff20cab 100644 --- a/src/pj_tsfn.c +++ b/src/pj_tsfn.c @@ -2,9 +2,15 @@ #include <math.h> #include <projects.h> - double -pj_tsfn(double phi, double sinphi, double e) { - sinphi *= e; - return (tan (.5 * (M_HALFPI - phi)) / - pow((1. - sinphi) / (1. + sinphi), .5 * e)); +double pj_tsfn(double phi, double sinphi, double e) { + double denominator; + sinphi *= e; + + /* avoid zero division, fail gracefully */ + denominator = 1.0 + sinphi; + if (denominator == 0.0) + return HUGE_VAL; + + return (tan (.5 * (M_HALFPI - phi)) / + pow((1. - sinphi) / (denominator), .5 * e)); } |