prefix_filename(): safely handle the case where pfx_len=0

diff --git a/xdiff/xutils.c b/xdiff/xutils.c
index bc12f298953a4e72b323f73607278028ec4a2805..ab6503460f760356a393a3c7b3b8438213e1ee94 100644 (file)
--- a/xdiff/xutils.c
+++ b/xdiff/xutils.c
@@ -190,8 +190,10 @@ int xdl_recmatch(const char *l1, long s1, const char *l2, long s2, long flags)
 {
        int i1, i2;
 
+       if (s1 == s2 && !memcmp(l1, l2, s1))
+               return 1;
        if (!(flags & XDF_WHITESPACE_FLAGS))
-               return s1 == s2 && !memcmp(l1, l2, s1);
+               return 0;
 
        i1 = 0;
        i2 = 0;
@@ -209,18 +211,18 @@ int xdl_recmatch(const char *l1, long s1, const char *l2, long s2, long flags)
                        if (l1[i1++] != l2[i2++])
                                return 0;
                skip_ws:
-                       while (i1 < s1 && isspace(l1[i1]))
+                       while (i1 < s1 && XDL_ISSPACE(l1[i1]))
                                i1++;
-                       while (i2 < s2 && isspace(l2[i2]))
+                       while (i2 < s2 && XDL_ISSPACE(l2[i2]))
                                i2++;
                }
        } else if (flags & XDF_IGNORE_WHITESPACE_CHANGE) {
                while (i1 < s1 && i2 < s2) {
-                       if (isspace(l1[i1]) && isspace(l2[i2])) {
+                       if (XDL_ISSPACE(l1[i1]) && XDL_ISSPACE(l2[i2])) {
                                /* Skip matching spaces and try again */
-                               while (i1 < s1 && isspace(l1[i1]))
+                               while (i1 < s1 && XDL_ISSPACE(l1[i1]))
                                        i1++;
-                               while (i2 < s2 && isspace(l2[i2]))
+                               while (i2 < s2 && XDL_ISSPACE(l2[i2]))
                                        i2++;
                                continue;
                        }
@@ -239,13 +241,13 @@ int xdl_recmatch(const char *l1, long s1, const char *l2, long s2, long flags)
         * while there still are characters remaining on both lines.
         */
        if (i1 < s1) {
-               while (i1 < s1 && isspace(l1[i1]))
+               while (i1 < s1 && XDL_ISSPACE(l1[i1]))
                        i1++;
                if (s1 != i1)
                        return 0;
        }
        if (i2 < s2) {
-               while (i2 < s2 && isspace(l2[i2]))
+               while (i2 < s2 && XDL_ISSPACE(l2[i2]))
                        i2++;
                return (s2 == i2);
        }
@@ -258,10 +260,10 @@ static unsigned long xdl_hash_record_with_whitespace(char const **data,
        char const *ptr = *data;
 
        for (; ptr < top && *ptr != '\n'; ptr++) {
-               if (isspace(*ptr)) {
+               if (XDL_ISSPACE(*ptr)) {
                        const char *ptr2 = ptr;
                        int at_eol;
-                       while (ptr + 1 < top && isspace(ptr[1])
+                       while (ptr + 1 < top && XDL_ISSPACE(ptr[1])
                                        && ptr[1] != '\n')
                                ptr++;
                        at_eol = (top <= ptr + 1 || ptr[1] == '\n');