fontselect: add and use strdup_trimmed

This is just a cleaner and safer interface for string trimming.

3 files changed, 20 insertions, 12 deletions

diff --git a/libass/ass_fontselect.c b/libass/ass_fontselect.c
index 95a4038..3fcd8c7 100644
--- a/libass/ass_fontselect.c
+++ b/libass/ass_fontselect.c
@@ -455,11 +455,14 @@ static char *select_font(ASS_FontSelector *priv, ASS_Library *library,
     int idx = -1;
     ASS_FontInfo req;
     char *req_fullname;
-    char *tfamily = trim_space(strdup(family));
+    char *family_trim = strdup_trimmed(family);
+
+    if (family_trim == NULL)
+        return NULL;
 
     ASS_FontProvider *default_provider = priv->default_provider;
     if (default_provider && default_provider->funcs.match_fonts)
-        default_provider->funcs.match_fonts(library, default_provider, tfamily);
+        default_provider->funcs.match_fonts(library, default_provider, family_trim);
 
     ASS_FontInfo *font_infos = priv->font_infos;
 
@@ -474,7 +477,7 @@ static char *select_font(ASS_FontSelector *priv, ASS_Library *library,
     req.width   = 100;
     req.n_fullname   = 1;
     req.fullnames    = &req_fullname;
-    req.fullnames[0] = tfamily;
+    req.fullnames[0] = family_trim;
 
     // match font
     unsigned score_min = UINT_MAX;
@@ -494,8 +497,8 @@ static char *select_font(ASS_FontSelector *priv, ASS_Library *library,
         }
     }
 
-    // free font request
-    free(req.fullnames[0]);
+    // free font name
+    free(family_trim);
 
     // found anything?
     if (idx < 0) {
diff --git a/libass/ass_utils.c b/libass/ass_utils.c
index 40e6533..06ae8c7 100644
--- a/libass/ass_utils.c
+++ b/libass/ass_utils.c
@@ -331,22 +331,26 @@ void ass_msg(ASS_Library *priv, int lvl, char *fmt, ...)
     va_end(va);
 }
 
-char *trim_space(char *str)
+/**
+ * Return a string with spaces trimmed at start and end.
+ * \param str input string
+ * \return output string, can be released with free()
+ */
+char *strdup_trimmed(const char *str)
 {
-    int i;
     int left = 0;
     int right = strlen(str) - 1;
+    char *out = NULL;
 
     while (isspace(str[left])) left++;
     while (right > left && isspace(str[right])) right--;
 
-    if (left > 0)
-        for (i = 0; i <= right - left; i++)
-            str[i] = str[left+i];
+    out = calloc(1, right-left+2);
 
-    str[right-left+1] = '\0';
+    if (out)
+        memcpy(out, str + left, right-left+1);
 
-    return str;
+    return out;
 }
 
 unsigned ass_utf8_get_char(char **str)
diff --git a/libass/ass_utils.h b/libass/ass_utils.h
index caff161..79fe589 100644
--- a/libass/ass_utils.h
+++ b/libass/ass_utils.h
@@ -91,6 +91,7 @@ int32_t parse_alpha_tag(char *str);
 uint32_t parse_color_tag(char *str);
 uint32_t parse_color_header(char *str);
 char *trim_space(char *str);
+char *strdup_trimmed(const char *str);
 char parse_bool(char *str);
 int parse_ycbcr_matrix(char *str);
 unsigned ass_utf8_get_char(char **str);