patch 8.1.1843: might be freeing memory that was not allocated

Problem:    Might be freeing memory that was not allocated.
Solution:   Have next_fenc() set the fenc_alloced flag. (closes #4804)

diff --git a/src/fileio.c b/src/fileio.c
index bc0b15b91496f519a9ed27bda4920859cbb1b2fc..e07b908671de5cc2b85485a7371e51df043c0e6a 100644 (file)
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -27,7 +27,7 @@
 /* Is there any system that doesn't have access()? */
 #define USE_MCH_ACCESS
 
-static char_u *next_fenc(char_u **pp);
+static char_u *next_fenc(char_u **pp, int *alloced);
 #ifdef FEAT_EVAL
 static char_u *readfile_charconvert(char_u *fname, char_u *fenc, int *fdp);
 #endif
@@ -890,8 +890,7 @@ readfile(
     else
     {
        fenc_next = p_fencs;            /* try items in 'fileencodings' */
-       fenc = next_fenc(&fenc_next);
-       fenc_alloced = TRUE;
+       fenc = next_fenc(&fenc_next, &fenc_alloced);
     }
 
     /*
@@ -994,8 +993,7 @@ retry:
                vim_free(fenc);
            if (fenc_next != NULL)
            {
-               fenc = next_fenc(&fenc_next);
-               fenc_alloced = (fenc_next != NULL);
+               fenc = next_fenc(&fenc_next, &fenc_alloced);
            }
            else
            {
@@ -2761,14 +2759,16 @@ set_forced_fenc(exarg_T *eap)
  * "pp" points to fenc_next.  It's advanced to the next item.
  * When there are no more items, an empty string is returned and *pp is set to
  * NULL.
- * When *pp is not set to NULL, the result is in allocated memory.
+ * When *pp is not set to NULL, the result is in allocated memory and "alloced"
+ * is set to TRUE.
  */
     static char_u *
-next_fenc(char_u **pp)
+next_fenc(char_u **pp, int *alloced)
 {
     char_u     *p;
     char_u     *r;
 
+    *alloced = FALSE;
     if (**pp == NUL)
     {
        *pp = NULL;
@@ -2791,8 +2791,11 @@ next_fenc(char_u **pp)
            r = p;
        }
     }
-    if (r == NULL)     /* out of memory */
+    if (r != NULL)
+       *alloced = TRUE;
+    else
     {
+       // out of memory
        r = (char_u *)"";
        *pp = NULL;
     }

diff --git a/src/version.c b/src/version.c
index 568852bbd2c0ded515a9fb6700e49fc3ec823df5..5741d5fdaacbacb2628385a99f3a12134de2eb88 100644 (file)
--- a/src/version.c
+++ b/src/version.c
@@ -769,6 +769,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1843,
 /**/
     1842,
 /**/