From 78c7bcc36adae4af583d24526352e75099c71291 Mon Sep 17 00:00:00 2001
From: ketmar <ketmar@ketmar.no-ip.org>
Date: Thu, 3 Oct 2013 16:09:39 +0300
Subject: [PATCH] dstrings: it's now safe to pass NULL dstring

---
 src/dstrings.c | 97 +++++++++++++++++++++++++++++++++++-----------------------
 1 file changed, 58 insertions(+), 39 deletions(-)

diff --git a/src/dstrings.c b/src/dstrings.c
index 7dda821..862270d 100644
--- a/src/dstrings.c
+++ b/src/dstrings.c
@@ -22,10 +22,12 @@
 
 
 static inline void dstr_zero (dstring_t *s) {
-  s->str = s->sbuf;
-  s->len = 0;
-  s->size = sizeof(s->sbuf);
-  s->sbuf[0] = 0;
+  if (s != NULL) {
+    s->str = s->sbuf;
+    s->len = 0;
+    s->size = sizeof(s->sbuf);
+    s->sbuf[0] = 0;
+  }
 }
 
 
@@ -53,56 +55,66 @@ void dstr_init_memrange (dstring_t *s, const void *start, const void *finish) {
 
 
 void dstr_done (dstring_t *s) {
-  if (s->str != s->sbuf) free(s->str);
-  dstr_zero(s);
+  if (s != NULL) {
+    if (s->str != s->sbuf) free(s->str);
+    dstr_zero(s);
+  }
 }
 
 
 void dstr_clear (dstring_t *s) {
-  s->str[s->len=0] = 0;
+  if (s != NULL) {
+    s->str[s->len=0] = 0;
+  }
 }
 
 
 void dstr_empty (dstring_t *s) {
-  if (s->str != s->sbuf) free(s->str);
-  dstr_zero(s);
+  if (s != NULL) {
+    if (s->str != s->sbuf) free(s->str);
+    dstr_zero(s);
+  }
 }
 
 
 static void dstr_resv (dstring_t *s, int size) {
-  if (size < 0) size = 0;
-  if (size > 0) {
-    if (s->str == s->sbuf) {
-      s->str = malloc(size);
-      if (s->len > 0) memcpy(s->str, s->sbuf, s->len);
-      s->str[s->len] = 0;
-    } else {
-      char *ns = realloc(s->str, size);
-      if (ns == NULL) { fprintf(stderr, "FATAL: out of memory!\n"); abort(); }
-      s->str = ns;
+  if (s != NULL) {
+    if (size < 0) size = 0;
+    if (size > 0) {
+      if (s->str == s->sbuf) {
+        s->str = malloc(size);
+        if (s->len > 0) memcpy(s->str, s->sbuf, s->len);
+        s->str[s->len] = 0;
+      } else {
+        char *ns = realloc(s->str, size);
+        if (ns == NULL) { fprintf(stderr, "FATAL: out of memory!\n"); abort(); }
+        s->str = ns;
+      }
     }
+    s->size = size;
   }
-  s->size = size;
 }
 
 
 void dstr_reserve (dstring_t *s, int size) {
-  if (size > s->size) dstr_resv(s, size);
+  if (s != NULL && size > s->size) dstr_resv(s, size);
 }
 
 
 // make room for at least `spc` chars
 static inline void dstr_expand (dstring_t *s, int spc) {
-  if (spc >= 0) dstr_reserve(s, ((s->len+spc+1)|0x3ff)+1);
+  if (s != NULL && spc >= 0) dstr_reserve(s, ((s->len+spc+1)|0x3ff)+1);
 }
 
 
 void dstr_push_buf (dstring_t *s, const void *start, int len) {
-  if (len < 0) len = (start != NULL ? strlen((const char *)start) : 0);
-  if (len > 0) {
-    dstr_expand(s, len);
-    if (start == NULL) memset(s->str+s->len, 32, len); else memmove(s->str+s->len, start, len);
-    s->str[s->len+=len] = 0;
+  if (s != NULL) {
+    if (len < 0) len = (start != NULL ? strlen((const char *)start) : 0);
+    if (len > 0) {
+      dstr_expand(s, len);
+      if (start == NULL) memset(s->str+s->len, 32, len); else memmove(s->str+s->len, start, len);
+      s->str[s->len+=len] = 0;
+    }
   }
 }
 
@@ -113,14 +125,16 @@ void dstr_push_cstr (dstring_t *s, const void *str) {
 
 
 void dstr_push_memrange (dstring_t *s, const void *start, const void *finish) {
-  if (finish > start) dstr_push_buf(s, start, ((const char *)finish)-((const char *)start));
+  if (s != NULL && finish > start) dstr_push_buf(s, start, ((const char *)finish)-((const char *)start));
 }
 
 
 void dstr_push_char (dstring_t *s, int x) {
-  dstr_expand(s, 1);
-  s->str[s->len++] = x&0xff;
-  s->str[s->len] = 0;
+  if (s != NULL) {
+    dstr_expand(s, 1);
+    s->str[s->len++] = x&0xff;
+    s->str[s->len] = 0;
+  }
 }
 
 
@@ -142,28 +156,33 @@ void dstr_set_memrange (dstring_t *s, const void *start, const void *finish) {
 
 
 void dstr_chop (dstring_t *s, int n) {
-  if (n < 0) n = 0; else if (n > s->len) n = s->len;
-  s->str[s->len=n] = 0;
+  if (s != NULL) {
+    if (n < 0) n = 0; else if (n > s->len) n = s->len;
+    s->str[s->len=n] = 0;
+  }
 }
 
 
 int dstr_pop_char (dstring_t *s) {
-  int res = (s->len > 0 ? (unsigned char)(s->str[--s->len]) : 0);
-  s->str[s->len] = 0;
-  return res;
+  if (s != NULL) {
+    int res = (s->len > 0 ? (unsigned char)(s->str[--s->len]) : 0);
+    s->str[s->len] = 0;
+    return res;
+  }
+  return 0;
 }
 
 
 char dstr_last_char (dstring_t *s) {
-  return (s->len > 0 ? s->str[s->len-1] : 0);
+  return (s != NULL && s->len > 0 ? s->str[s->len-1] : 0);
 }
 
 
 char *dstr_cstr (dstring_t *s) {
-  return s->str;
+  return (s != NULL ? s->str : NULL);
 }
 
 
 int dstr_len (dstring_t *s) {
-  return s->len;
+  return (s != NULL ? s->len : 0);
 }
-- 
2.11.4.GIT