Better handling of invalid TZIDs that look like GMT+05:00

This will fix problems with parsing parameters that come after a TZID parameter

1 files changed, 19 insertions, 5 deletions

diff --git a/src/libical/icalparser.c b/src/libical/icalparser.c
index ef33617f..c5088fcc 100644
--- a/src/libical/icalparser.c
+++ b/src/libical/icalparser.c
@@ -919,18 +919,22 @@ icalcomponent* icalparser_add_line(icalparser* parser,
                 icalparameter_set_xname(param,name);
                 icalparameter_set_xvalue(param,pvalue);
             }
-        } else if (kind == ICAL_TZID_PARAMETER){
+        } else if (kind == ICAL_TZID_PARAMETER && *(end - 1) != ';'){
             /*
-             Special case handling for TZID to workaround invalid incoming data.
+             Special case handling for TZID to work around invalid incoming data.
              For example, Google Calendar will send back stuff like this:
              DTSTART;TZID=GMT+05:30:20120904T020000
            
-             In this case we read to the last colon rather than the first colon.
+             In this case we read to the next semicolon or the last colon rather than the first colon.
              This way the TZID will become GMT+05:30 rather than trying to parse
              the date-time as 30:20120904T020000.
+             
+             This also handles properties that look like this:
+             DTSTART;TZID=GMT+05:30;VALUE=DATE-TIME:20120904T020000
              */
             char *lastColon = 0;
             char *nextColon = end;
+            char *nextSemicolon = parser_get_next_char(';', end, 1);
           
             /* Find the last colon in the line */
             do {
@@ -940,14 +944,24 @@ icalcomponent* icalparser_add_line(icalparser* parser,
                     lastColon = nextColon;
                 }
             } while (nextColon);
+            
+            if (lastColon && nextSemicolon && nextSemicolon < lastColon) {
+                /*
+                 Ensures that we don't read past a semicolon
+                 
+                 Handles the following line:
+                 DTSTART;TZID=GMT+05:30;VALUE=DATE-TIME:20120904T020000
+                */
+                lastColon = nextSemicolon;
+            }
           
             /*
-             Rebuild str so that it includes everything up to the last colon.
+             Rebuild str so that it includes everything up to the next semicolon or the last colon.
              So given the above example, str will go from
              "TZID=GMT+05" to "TZID=GMT+05:30"
              */
             if (lastColon && *(lastColon + 1) != 0) {
-                char *strStart = line + sizeof(str);
+                char *strStart = line + strlen(name) + 2;
               
                 end = lastColon + 1;