liblib: Added negative %variable lengths to count backwards from the end of the value.

For example %0.-2 for "12345" returns "123".
Patch by Norbert Weinhold / Open-Xchange.

diff --git a/src/lib/var-expand.c b/src/lib/var-expand.c
index 04b07aa140aedf737f193bbe735627bd804f3d13..35b6f80f56b4607fa2060776dca1a45a57ceac4d 100644 (file)
--- a/src/lib/var-expand.c
+++ b/src/lib/var-expand.c
@@ -19,7 +19,7 @@
 
 struct var_expand_context {
        int offset;
-       unsigned int width;
+       int width;
        bool zero_padding;
 };
 
@@ -268,7 +268,8 @@ void var_expand_with_funcs(string_t *dest, const char *str,
                        }
 
                        if (*str == '.') {
-                               ctx.offset = sign * (int)ctx.width;
+                               ctx.offset = sign * ctx.width;
+                               sign = 1;
                                ctx.width = 0;
                                str++;
 
@@ -280,11 +281,16 @@ void var_expand_with_funcs(string_t *dest, const char *str,
                                        ctx.zero_padding = TRUE;
                                        str++;
                                }
+                               if (*str == '-') {
+                                       sign = -1;
+                                       str++;
+                               }
 
                                while (*str >= '0' && *str <= '9') {
                                        ctx.width = ctx.width*10 + (*str - '0');
                                        str++;
                                }
+                               ctx.width = sign * ctx.width;
                        }
 
                         modifier_count = 0;
@@ -350,11 +356,13 @@ void var_expand_with_funcs(string_t *dest, const char *str,
                                }
                                if (ctx.width == 0)
                                        str_append(dest, var);
-                               else if (!ctx.zero_padding)
+                               else if (!ctx.zero_padding) {
+                                       if (ctx.width < 0)
+                                               ctx.width = strlen(var) - (-ctx.width);
                                        str_append_n(dest, var, ctx.width);
-                               else {
+                               } else {
                                        /* %05d -like padding. no truncation. */
-                                       size_t len = strlen(var);
+                                       int len = strlen(var);
                                        while (len < ctx.width) {
                                                str_append_c(dest, '0');
                                                ctx.width--;
@@ -392,7 +400,7 @@ void var_get_key_range(const char *str, unsigned int *idx_r,
 
        if (str[i] == '.') {
                i++;
-               while (str[i] >= '0' && str[i] <= '9')
+               while ((str[i] >= '0' && str[i] <= '9') || str[i] == '-')
                        i++;
        }