Add support for escaped quotes, semicolon and hash in quoted values

This commit will fix an inconsistency in the behavior of `iniparser_set()`
and `iniparser_load()`. It will also make sure that dumping working
dictionary results in an INI file which provides the same dictionary
after loading this INI.

The inconsistency is:

- `iniparser_set()` supports escaped quotes, semicolon and hash in values:
```
"str\"ing" => str"ing
"str;ing" => str;ing
"str#ing" => str#ing
```

-`iniparser_load()` does not support semicolon and hash in unquoted values:
```
str;ing => str
str#ing => str
```
Which is correct, because in this case semicolon and hash indicate that the
rest of the line is a comment.

- `iniparser_load()` supports quotes in unquoted values
```
 str"ing => str"ing
```
- `iniparser_load()` supports semicolon and hash in quoted values:

```
"str;ing" => str;ing
"str#ing" => str#ing
```


However, before this commit:

- `iniparser_load()` did not support escaped quotes in quoted values:

```
"str\"ing" => str\
```

And:

- `iniparser_dump_ini()` wrote all values without quotes

The implemented fix is:

- `iniparser_load()` supports escaping iff the value is quoted
- `iniparser_dump_ini()` will quote all values and escape '\' and '"'

These changes do not break existing test cases.

refs #97

src/iniparser.c

@@ -247,6 +247,26 @@ void iniparser_dump(const dictionary * d, FILE * f)
     return ;
 }
 
+static void escape_value(char *escaped, char *value) {
+    char c;
+    int v = 0;
+    int e = 0;
+
+    if(!escaped || !value)
+        return;
+
+    while((c = value[v]) != '\0') {
+        if(c == '\\' || c == '"') {
+            escaped[e] = '\\';
+            e++;
+        }
+        escaped[e] = c;
+        v++;
+        e++;
+    }
+    escaped[e] = '\0';
+}
+
 /*-------------------------------------------------------------------------*/
 /**
   @brief    Save a dictionary to a loadable ini file
@@ -263,6 +283,7 @@ void iniparser_dump_ini(const dictionary * d, FILE * f)
     size_t       i ;
     size_t       nsec ;
     const char * secname ;
+    char escaped[ASCIILINESZ+1] = "";
 
     if (d==NULL || f==NULL) return ;
 
@@ -272,7 +293,8 @@ void iniparser_dump_ini(const dictionary * d, FILE * f)
         for (i=0 ; i<d->size ; i++) {
             if (d->key[i]==NULL)
                 continue ;
-            fprintf(f, "%s = %s\n", d->key[i], d->val[i]);
+            escape_value(escaped, d->val[i]);
+            fprintf(f, "%s = \"%s\"\n", d->key[i], escaped);
         }
         return ;
     }
@@ -301,6 +323,7 @@ void iniparser_dumpsection_ini(const dictionary * d, const char * s, FILE * f)
     size_t  j ;
     char    keym[ASCIILINESZ+1];
     int     seclen ;
+    char escaped[ASCIILINESZ+1] = "";
 
     if (d==NULL || f==NULL) return ;
     if (! iniparser_find_entry(d, s)) return ;
@@ -312,10 +335,8 @@ void iniparser_dumpsection_ini(const dictionary * d, const char * s, FILE * f)
         if (d->key[j]==NULL)
             continue ;
         if (!strncmp(d->key[j], keym, seclen+1)) {
-            fprintf(f,
-                    "%-30s = %s\n",
-                    d->key[j]+seclen+1,
-                    d->val[j] ? d->val[j] : "");
+            escape_value(escaped, d->val[j]);
+            fprintf(f, "%-30s = \"%s\"\n", d->key[j]+seclen+1, escaped);
         }
     }
     fprintf(f, "\n");
@@ -642,6 +663,44 @@ void iniparser_unset(dictionary * ini, const char * entry)
     dictionary_unset(ini, strlwc(entry, tmp_str, sizeof(tmp_str)));
 }
 
+static void parse_quoted_value(char *value, char quote) {
+    char c;
+    char *quoted;
+    int q = 0, v = 0;
+    int esc = 0;
+
+    if(!value)
+        return;
+
+    quoted = xstrdup(value);
+
+    if(!quoted) {
+        iniparser_error_callback("iniparser: memory allocation failure\n");
+        goto end_of_value;
+    }
+
+    while((c = quoted[q]) != '\0') {
+        if(!esc) {
+            if(c == '\\') {
+                esc = 1;
+                q++;
+                continue;
+            }
+
+            if(c == quote) {
+                goto end_of_value;
+            }
+        }
+        esc = 0;
+        value[v] = c;
+        v++;
+        q++;
+    }
+end_of_value:
+    value[v] = '\0';
+    free(quoted);
+}
+
 /*-------------------------------------------------------------------------*/
 /**
   @brief    Load a single line from an INI file
@@ -661,6 +720,7 @@ static line_status iniparser_line(
     line_status sta ;
     char * line = NULL;
     size_t      len ;
+    int d_quote;
 
     line = xstrdup(input_line);
     len = strstrip(line);
@@ -678,11 +738,15 @@ static line_status iniparser_line(
         strstrip(section);
         strlwc(section, section, len);
         sta = LINE_SECTION ;
-    } else if (sscanf (line, "%[^=] = \"%[^\"]\"", key, value) == 2
-           ||  sscanf (line, "%[^=] = '%[^\']'",   key, value) == 2) {
+    } else if ((d_quote = sscanf (line, "%[^=] = \"%[^\n]\"", key, value)) == 2
+               ||  sscanf (line, "%[^=] = '%[^\n]'",   key, value) == 2) {
         /* Usual key=value with quotes, with or without comments */
         strstrip(key);
         strlwc(key, key, len);
+        if(d_quote == 2)
+            parse_quoted_value(value, '"');
+        else
+            parse_quoted_value(value, '\'');
         /* Don't strip spaces from values surrounded with quotes */
         sta = LINE_VALUE ;
     } else if (sscanf (line, "%[^=] = %[^;#]", key, value) == 2) {

src/iniparser.h

@@ -82,6 +82,13 @@ const char * iniparser_getsecname(const dictionary * d, int n);
 
   This function dumps a given dictionary into a loadable ini file.
   It is Ok to specify @c stderr or @c stdout as output files.
+
+  All values are quoted these charecters are escaped:
+
+  ” - the quote character (e.g. “String with ”Quotes””)
+
+  \ - the backslash character (e.g. “C:\tmp”)
+
  */
 /*--------------------------------------------------------------------------*/
 
@@ -382,6 +389,17 @@ int iniparser_find_entry(const dictionary * ini, const char * entry) ;
   should not be accessed directly, but through accessor functions
   instead.
 
+  Iff the value is a quoted string it supports some escape sequences:
+
+  ” - the quote character (e.g. “String with ”Quotes””)
+
+  \ - the backslash character (e.g. “C:\tmp”)
+
+  Escape sequences always start with a backslash. Additional escape sequences
+  might be added in the future. Backslash characters must be escaped. Any other
+  sequence then those outlined above is invalid and may lead to unpredictable
+  results.
+
   The returned dictionary must be freed using iniparser_freedict().
  */
 /*--------------------------------------------------------------------------*/

test/test_iniparser.c

@@ -1066,11 +1066,7 @@ void Test_iniparser_quotes(CuTest *tc)
         goto rm_ini;
     }
 
-    /*
-     * iniparser_load() does not support escaped quotes in values if they are
-     * quoted
-     */
-    CuAssertStrEquals(tc, "str\\", iniparser_getstring(dic,
+    CuAssertStrEquals(tc, QUOTES_INI_VAL0, iniparser_getstring(dic,
                       QUOTES_INI_SEC ":" QUOTES_INI_ATTR0, NULL));
     /*
      * iniparser_load() supports semicolon and hash in values if they are
@@ -1089,7 +1085,7 @@ void Test_iniparser_quotes(CuTest *tc)
     /*
      * iniparser_load() supports quotes in attributes
      */
-    CuAssertStrEquals(tc, "str\\", iniparser_getstring(dic,
+    CuAssertStrEquals(tc, QUOTES_INI_VAL0, iniparser_getstring(dic,
                       QUOTES_INI_SEC ":" "str\"ing", NULL));
     /*
      * iniparser_load() does not support semicolon or hash in attributes
@@ -1101,8 +1097,50 @@ void Test_iniparser_quotes(CuTest *tc)
     /*
      * iniparser_load() does support colon in attributes
      */
-    CuAssertStrEquals(tc, "str\\", iniparser_getstring(dic,
+    CuAssertStrEquals(tc, QUOTES_INI_VAL0, iniparser_getstring(dic,
                       QUOTES_INI_SEC ":" "str:ing", NULL));
+    ini = fopen(TMP_INI_PATH, "w+");
+
+    if (!ini) {
+        fprintf(stderr, "iniparser: cannot open %s\n", TMP_INI_PATH);
+        goto del_dic;
+    }
+
+    /**
+     * Test iniparser_dump_ini()
+     */
+    iniparser_dump_ini(dic, ini);
+    fclose(ini);
+    dictionary_del(dic);
+    dic = iniparser_load(TMP_INI_PATH);
+
+    CuAssertStrEquals(tc, QUOTES_INI_VAL0, iniparser_getstring(dic,
+                      QUOTES_INI_SEC ":" QUOTES_INI_ATTR0, NULL));
+    CuAssertStrEquals(tc, QUOTES_INI_VAL1, iniparser_getstring(dic,
+                      QUOTES_INI_SEC ":" QUOTES_INI_ATTR1, NULL));
+    CuAssertStrEquals(tc, QUOTES_INI_VAL2, iniparser_getstring(dic,
+                      QUOTES_INI_SEC ":" QUOTES_INI_ATTR2, NULL));
+    CuAssertStrEquals(tc, QUOTES_INI_VAL0, iniparser_getstring(dic,
+                      QUOTES_INI_SEC ":" QUOTES_INI_ATTR3, NULL));
+    CuAssertStrEquals(tc, "str", iniparser_getstring(dic,
+                      QUOTES_INI_SEC ":" QUOTES_INI_ATTR4, NULL));
+    CuAssertStrEquals(tc, "str", iniparser_getstring(dic,
+                      QUOTES_INI_SEC ":" QUOTES_INI_ATTR5, NULL));
+    CuAssertStrEquals(tc, QUOTES_INI_VAL0, iniparser_getstring(dic,
+                      QUOTES_INI_SEC ":" "str\"ing", NULL));
+    CuAssertStrEquals(tc, NULL, iniparser_getstring(dic,
+                      QUOTES_INI_SEC ":" "str;ing", NULL));
+    CuAssertStrEquals(tc, NULL, iniparser_getstring(dic,
+                      QUOTES_INI_SEC ":" "str#ing", NULL));
+    CuAssertStrEquals(tc, QUOTES_INI_VAL0, iniparser_getstring(dic,
+                      QUOTES_INI_SEC ":" "str:ing", NULL));
+    dictionary_del(dic);
+    ret = remove(TMP_INI_PATH);
+
+    if (ret) {
+        fprintf(stderr, "cannot remove file: %s\n", TMP_INI_PATH);
+        return;
+    }
     /**
      * test iniparser_set()
      */
@@ -1197,8 +1235,7 @@ void Test_iniparser_quotes(CuTest *tc)
         goto rm_ini;
     }
 
-    /* iniparser_load() does not support ; in values */
-    CuAssertStrEquals(tc, "str", iniparser_getstring(dic,
+    CuAssertStrEquals(tc, QUOTES_INI_VAL1, iniparser_getstring(dic,
                       QUOTES_INI_SEC ":" QUOTES_INI_ATTR1, NULL));
     dictionary_del(dic);
     ret = remove(TMP_INI_PATH);
@@ -1250,8 +1287,7 @@ void Test_iniparser_quotes(CuTest *tc)
         goto rm_ini;
     }
 
-    /* iniparser_load() does not support ; in values */
-    CuAssertStrEquals(tc, "str", iniparser_getstring(dic,
+    CuAssertStrEquals(tc, QUOTES_INI_VAL2, iniparser_getstring(dic,
                       QUOTES_INI_SEC ":" QUOTES_INI_ATTR2, NULL));
 del_dic:
     dictionary_del(dic);