Fix handling of time zones less than an hour before UTC

Time zone offsets between -1:00 and 00:00 were being incorrectly
handled. Such a time zone does not actually exist today, but if it ever
does it will now work.

Author: dfandrich

main-command.c

@@ -479,7 +479,8 @@ int main(int argc, char** argv)
 					{
 						/* Found colon. Split into two. */
 						sscanf(optarg, "%d:%d", &TimeZoneHours, &TimeZoneMins);
-						if (TimeZoneHours < 0)
+						/* Can't look at sign of TimeZoneHours because it might be -0 */
+						if (*optarg == '-')
 						    TimeZoneMins *= -1;
 					} else {
 						/* No colon. Just parse. */

tests/data/test177.param

@@ -1,4 +1,4 @@
-# End result is same as test 29
+# End location is the same as test 29
 TITLE='Correlate a file with subsecond interpolation and fractional photooffset'
 PRECOMMAND='cat "$STAGINGDIR/point1-4.jpg" >"$LOGDIR/test.jpg"'
 # Run in C locale to correctly parse these decimal numbers

tests/data/test185.param

@@ -0,0 +1,6 @@
+# End result is the same as test 29
+TITLE='Correlate a file with -00:30 time zone'
+PRECOMMAND='cat "$STAGINGDIR/point1-1.jpg" >"$LOGDIR/test.jpg"'
+COMMAND='$PROGRAM -t -z -00:30 -O -1800 -g "$STAGINGDIR/track2.gpx" "$LOGDIR/test.jpg" > "$OUTFILE" 2>&1 && exiv2 -pv pr "$LOGDIR/test.jpg" >> "$OUTFILE" 2>&1'
+POSTCOMMAND='rm -f "$LOGDIR/test.jpg"'
+RESULTCODE=0

tests/data/test185.result

@@ -0,0 +1,35 @@
+Reading GPS Data...
+Legend: . = Ok, / = Interpolated, < = Rounded, - = No match, ^ = Too far
+        w = Write Fail, ? = No EXIF date, ! = GPS already present
+
+Correlate: /
+
+Completed correlation process.
+Matched:     1 (0 Exact, 1 Interpolated, 0 Rounded).
+Failed:      0 (0 Not matched, 0 Write failure, 0 Too Far,
+                0 No Date, 0 GPS Already Present.)
+0x011a Image        XResolution                 Rational    1  72/1
+0x011b Image        YResolution                 Rational    1  72/1
+0x0128 Image        ResolutionUnit              Short       1  2
+0x0132 Image        DateTime                    Ascii      20  2012:11:22 12:34:56
+0x0213 Image        YCbCrPositioning            Short       1  1
+0x8769 Image        ExifTag                     Long        1  134
+0x9000 Photo        ExifVersion                 Undefined   4  48 50 49 48
+0x9003 Photo        DateTimeOriginal            Ascii      20  2012:11:22 12:34:56
+0x9004 Photo        DateTimeDigitized           Ascii      20  2012:11:22 12:34:56
+0x9101 Photo        ComponentsConfiguration     Undefined   4  1 2 3 0
+0xa000 Photo        FlashpixVersion             Undefined   4  48 49 48 48
+0xa001 Photo        ColorSpace                  Short       1  65535
+0xa002 Photo        PixelXDimension             Long        1  64
+0xa003 Photo        PixelYDimension             Long        1  64
+0x8825 Image        GPSTag                      Long        1  276
+0x0000 GPSInfo      GPSVersionID                Byte        4  2 2 0 0
+0x0001 GPSInfo      GPSLatitudeRef              Ascii       2  N
+0x0002 GPSInfo      GPSLatitude                 Rational    3  47/1 25/1 16449600/1000000
+0x0003 GPSInfo      GPSLongitudeRef             Ascii       2  E
+0x0004 GPSInfo      GPSLongitude                Rational    3  10/1 59/1 6888000/1000000
+0x0005 GPSInfo      GPSAltitudeRef              Byte        1  0
+0x0006 GPSInfo      GPSAltitude                 Rational    1  2959867/1000
+0x0007 GPSInfo      GPSTimeStamp                Rational    3  12/1 34/1 56/1
+0x0012 GPSInfo      GPSMapDatum                 Ascii       7  WGS-84
+0x001d GPSInfo      GPSDateStamp                Ascii      11  2012:11:22