eina: fix for escapable charachters not getting escaped if it comes after '\t' or '\n'

Summary:
Escaping is not happening whenever any escapable characters is coming after
'\t' or '\n'. It will also fix invalid read of 1 byte which happens for string where
last charachter is '\t' or '\n' like "eina\t".

Test Plan:
Take a string like "eina\t ". Observe space which is followed by tab is not getting
escaped.

Signed-off-by: Prasoon Singh <prasoon.16@samsung.com>

Reviewers: shilpasingh, rajeshps, govi, cedric

Reviewed By: shilpasingh

Subscribers: cedric, jpeg

Differential Revision: https://phab.enlightenment.org/D4847

Signed-off-by: Cedric BAIL <cedric@osg.samsung.com>

AUTHORS

@@ -54,7 +54,8 @@ Rajeev Ranjan (Rajeev) <rajeev.r@samsung.com> <rajeev.jnnce@gmail.com>
 Subodh Kumar <s7158.kumar@samsung.com>
 Michelle Legrand <legrand.michelle@outlook.com>
 Shilpa Singh <shilpa.singh@samsung.com> <shilpasingh.o@gmail.com>
-
+Prasoon Singh <prasoonsingh16@gmail.com>
+ 
 Eet
 ---
 

src/lib/eina/eina_str.c

@@ -668,24 +668,27 @@ eina_str_escape(const char *str)
            {
              *d = '\\';
              d++;
+             *d = *s;
              break;
            }
          case '\n':
            {
              *d = '\\'; d++;
-             *d = 'n'; d++;
+             *d = 'n';
-             s++;
              break;
            }
          case '\t':
            {
              *d = '\\'; d++;
-             *d = 't'; d++;
+             *d = 't';
-             s++;
+             break;
+           }
+         default:
+           {
+             *d = *s;
              break;
            }
         }
-        *d = *s;
      }
    *d = 0;
    return s2;

src/tests/eina/eina_test_str.c

@@ -108,6 +108,13 @@ START_TEST(str_simple)
    free(str);
    free(ret);
 
+   str = malloc(sizeof(char) * 4);
+   strcpy(str, "a\t ");
+   ret = eina_str_escape(str);
+   fail_if(!eina_streq(ret, "a\\t\\ "));
+   free(str);
+   free(ret);
+
    eina_shutdown();
 }
 END_TEST