1 files changed, 68 insertions, 44 deletions

diff --git a/ext/date/date_parse.c b/ext/date/date_parse.c
index ab46bda4ad..8717850eba 100644
--- a/ext/date/date_parse.c
+++ b/ext/date/date_parse.c
@@ -361,64 +361,88 @@ do { \
 #include "zonetab.h"
 
 static int
-str_end_with(const char *s, long l, const char *w)
+str_end_with_word(const char *s, long l, const char *w)
 {
     int n = (int)strlen(w);
-    return (l >= n && strncmp(s - n, w, n) == 0);
+    if (l <= n || !isspace(s[l - n - 1])) return 0;
+    if (strncasecmp(&s[l - n], w, n)) return 0;
+    do ++n; while (l > n && isspace(s[l - n - 1]));
+    return n;
 }
 
-VALUE
-date_zone_to_diff(VALUE str)
+static long
+shrunk_size(const char *s, long l)
 {
-    VALUE offset = Qnil;
-    VALUE vbuf = 0;
-
-    long l, i;
-    char *s, *dest, *d;
-    int sp = 1;
-
-    l = RSTRING_LEN(str);
-    s = RSTRING_PTR(str);
-
-    dest = d = ALLOCV_N(char, vbuf, l + 1);
-
-    for (i = 0; i < l; i++) {
-	if (isspace((unsigned char)s[i]) || s[i] == '\0') {
-	    if (!sp)
-		*d++ = ' ';
-	    sp = 1;
+    long i, ni;
+    int sp = 0;
+    for (i = ni = 0; i < l; ++i) {
+	if (!isspace(s[i])) {
+	    if (sp) ni++;
+	    sp = 0;
+	    ni++;
 	}
 	else {
-	    if (isalpha((unsigned char)s[i]))
-		*d++ = tolower((unsigned char)s[i]);
-	    else
-		*d++ = s[i];
-	    sp = 0;
+	    sp = 1;
 	}
     }
-    if (d > dest) {
-	if (*(d - 1) == ' ')
-	    --d;
-	*d = '\0';
+    return ni < l ? ni : 0;
+}
+
+static long
+shrink_space(char *d, const char *s, long l)
+{
+    long i, ni;
+    int sp = 0;
+    for (i = ni = 0; i < l; ++i) {
+	if (!isspace(s[i])) {
+	    if (sp) d[ni++] = ' ';
+	    sp = 0;
+	    d[ni++] = s[i];
+	}
+	else {
+	    sp = 1;
+	}
     }
-    l = d - dest;
-    s = dest;
+    return ni;
+}
+
+VALUE
+date_zone_to_diff(VALUE str)
+{
+    VALUE offset = Qnil;
+    VALUE vbuf = 0;
+    long l = RSTRING_LEN(str);
+    const char *s = RSTRING_PTR(str);
+
     {
-	static const char STD[] = " standard time";
-	static const char DST1[] = " daylight time";
-	static const char DST2[] = " dst";
 	int dst = 0;
+	int w;
 
-	if (str_end_with(d, l, STD)) {
-	    l -= sizeof(STD) - 1;
+	if ((w = str_end_with_word(s, l, "time")) > 0) {
+	    int wtime = w;
+	    l -= w;
+	    if ((w = str_end_with_word(s, l, "standard")) > 0) {
+		l -= w;
+	    }
+	    else if ((w = str_end_with_word(s, l, "daylight")) > 0) {
+		l -= w;
+		dst = 1;
+	    }
+	    else {
+		l += wtime;
+	    }
 	}
-	else if (str_end_with(d, l, DST1)) {
-	    l -= sizeof(DST1) - 1;
+	else if ((w = str_end_with_word(s, l, "dst")) > 0) {
+	    l -= w;
 	    dst = 1;
 	}
-	else if (str_end_with(d, l, DST2)) {
-	    l -= sizeof(DST2) - 1;
-	    dst = 1;
+	{
+	    long sl = shrunk_size(s, l);
+	    if (sl) {
+		char *d = ALLOCV_N(char, vbuf, sl);
+		l = shrink_space(d, s, l);
+		s = d;
+	    }
 	}
 	{
 	    const struct zone *z = zonetab(s, (unsigned int)l);
@@ -436,8 +460,8 @@ date_zone_to_diff(VALUE str)
 	    long hour = 0, min = 0, sec = 0;
 
 	    if (l > 3 &&
-		(strncmp(s, "gmt", 3) == 0 ||
-		 strncmp(s, "utc", 3) == 0)) {
+		(strncasecmp(s, "gmt", 3) == 0 ||
+		 strncasecmp(s, "utc", 3) == 0)) {
 		s += 3;
 		l -= 3;
 	    }